Studies in Mycology no. 7

 

10 June 1974

 

THE GENERA BLASTOBOTRYS, SPOROTHRIX, CALCARISPORIUM AND CALCARISPORIELLA GEN. NOV.

 

 

G. S. DE HOOG

Centraalbureau voor Schimmelcultures, Baarn.

 

 

 Summary

 

The genus Blastobotrys v. Klopotek, comprising only one species, is described. The Ascomycete genus Ceratocystis Ellis & Halst. is divided into two separate genera, mainly on account of the morphology of the conidial states: Ceratocystis sensu str. comprises species with Chalara, Chalaropsis and Thielaviopsis conidial states, whereas the majority of species of Ceratocystis auctt. has Sporothrix, Verticicladiella and Graphium states and is classified in Ophiostoma H. & P. Syd. Four new combinations in Ophiostoma are proposed. The concept of Sporothrix Hektoen & Perkins ex Nicot & Mariat is enlarged considerably. The presence of more or less differentiated conidiogenous cells, conspicuous denticles, and one-celled, hyaline conidia are regarded as diagnostic characteristics. The genus comprises 24 species; most of them are described and depicted. Six species are described as new, and 3 new combinations are proposed; 13 are conidial states of Ophiostoma. One species is excluded from Sporothrix and redescribed in Nodulisporium. A new genus, Calcarisporiella, is described. It can be recognized by the peculiar shape of the conidiogenous cells. Calcarisporium Preuss is restricted to one species, which can be distinguished by erect, verticillate conidiophores and determinate conidiogenous cells. A list of doubtful and excluded species of Calcarisporium is provided.

 

 

 INTRODUCTION

 

In recent years classification of Hyphomycetes has been increasingly guided by comparative studies of conidium ontogeny. Research into details of sympodial conidium formation was done i.a. by Kendrick & Cole (1968) with Beauveria globulifera (Speg.) Picard [= B. bassiana (Bals.) Vuill.], and by Cole (in Kendrick, 1972) with Tritirachium album Limber [= Beauveria alba (Limber) Saccas]. In both studies it was concluded that each conidium is formed as a blown-out end of the tip of the conidiogenous cell and becomes delimited by a double septum at its base. The conidiogenous cell proliferates just below and gives rise to a new terminal conidium. Thus in Beauveria Vuill. a denticulate, geniculate rachis is formed. De Hoog (1972) considered such a rachis as of diagnostic value for the genus: the denticulation distinguished it from Tritirachium Limber, and the genicula­tion separated Beauveria from Isaria sensu str. [p. 2]

The study of genera related to Beauveria was continued with Sporothrix, Blastobotrys, and Calcarisporium. Also in these genera the details of conidium formation appeared to be an important aid in classification.

 

 

 MATERIAL AND METHODS

 

 

For the present study all CBS strains of Sporothrix and allied genera were grown on oat-meal agar or 2% malt agar in daylight at room temperature (unless stated otherwise) and examined after 3, 10 and 30 days. To study the process of conidium formation a simple culture chamber was used, modified according to Cole & Kendrick (1968) and Cole & al. (1969). A sterilized slide was covered with a thin layer of nutrient medium and placed on a U-shaped glass bar in a petri-dish. Two narrow strips of medium were removed, leaving furrows from the side toward the middle (Fig. 1). The sides of the fissure were inoculated and covered with a sterilized coverslip; a small opening for aeration was left. The petri-dish was partially filled with water and sealed to prevent desiccation during the first days of growth without sporulation. The slide could be directly examined under the light microscope at high magnifications.

 

 

Fig.1. Culture chamber for study of conidium ontogeny. a. seen from above; b. side view.

 

Yeast-like states were studied in liquid media as described by Mariat & de Bièvre (1968), shaken for 14 days (Gagnon, 1961) at 25 or 37°C, depending on the species.

In Ceratocystis and allied genera of Ascomycetes the best results in inducing the formation of ascomata in pure culture were obtained in darkness at low temperatures. Nevertheless only a small percentage of the strains produced ripe perithecia. [p. 3]

Abbreviations of names of institutes and herbaria are those of Lanjouw & Stafleu (104) and the CBS List of Cultures (1972).

 

 

 MORPHOLOGY AND CLASSIFICATION

 

Ramification. Most species of the group of Hyphomycetes concerned in this study are composed of undifferentiated hyphae only. The conidia are formed on lateral cells, which are of more or less constant shape and usually slightly taper towards the tip. In creeping hyphae the conidiogenous cells may arise from any place of the hyphal cell, their occurrence is not correlated with the siting of septa (orthotropic branching, Gams, 1971; Fig. 2a). Often the conidiogenous cell becomes longer, septate, and inte­grates in the stalk of a short lateral branch (Fig. 2b) of indefinite length. In some species the lower cells of a few lateral branches may become slightly pigmented, e.g., in Sporothrix ramosissima sp. nov. (Fig. 2c).

Conidiogenous cells in this species may also be pallidly pigmented near the base and remain aseptate.

 

 

Fig. 2. Diagram of branching patterns. a-c. orthotropic branching; d-g. plagiotropic branching

 

In ascending or suberect hyphae the locus directly behind a septum can grow out and give rise to a branch or a conidiogenous cell, which forms a sharp angle with the supporting hypha (plagiotropic branching, Gams, 1971; Fig. 2g). In species with a compact mycelium most of the hyphae are suberect; occasionally some of them become slightly pigmented (Fig. 2f). Only in Blastobotrys nivea v. Klopotek do the fertile hyphae protrude above the sterile hyphae in such a way that the term ‘conidiophore’ is significant. This term is also applied in Calcarisporium arbuscula Preuss, [p.4] a species with a large, erect, verticillate conidial apparatus (Fig. 2d).

The branching system is usually progressive. In closely related groups, e.g., in Raffaelea-like Hyphomycetes and in Graphium ulmi Schwarz, re­trogressive branching (Kendrick, 1972) may occur. The basal cell of each branch is usually formed only when the branch has reached a definite length. If growth ceases before this length has been attained, the septum is often not formed.

 

Conidial production. In the species concerned in this paper the conidia are formed sympodially; only the secondary conidia of Blastobotrys nivea arise more or less synchronously (Kendrick, 1972). Growth of the conidio­genous cell may cease after formation of the first conidium. Thus the conidium-bearing denticles become clustered at the tip of the cell (Cepha­losporium, Hedgcock, 1906; Rhinotrichum, Georgescu & Orenski, 1957; Cylindrocephalum, Robak, 1932). If proliferation takes place, a denticulate rachis is formed. In numerous species short chains of secondary conidia are formed, the apical conidium being the youngest (Cladosporium, Lagerberg & al., 1927; Hormodendron, Robak, 1932; Hyalodendron, Goidànich, 1936b). Occasionally the primary conidia remain attached for a long time to the conidiogenous cell like ramo-conidia. In Blastobotrys nivea they are well differentiated and have been called ‘Sporenmutterzellen’ by von Klopotek (1967).

 

Pleomorphy. In many species some of the detached conidia become inflated, more or less spherical, and form blastoconidia by multipolar budding (Blastomyces, Goidànich, 1936a; Dematium, Grosmann, 1930; Pionnotes, Georgescu & Orenski, 1957). Conidium ontogeny in these so-called yeast-forms is the same as in Sporothrix (Taylor, 1970a). Sometimes the budding cells can be distinguished with difficulty from secondary conidia formed on hyphal cells.

Scattered blastoconidia may arise along the sides of mature hyphae (Humicola, de Bertoldi & al., 1972). They have been described in detail by Mariat & al. (1962). In some species they are more abundant when sporulation of the Sporothrix state has decreased.

Endoconidia (Dolichoascus, Ansel & Thibaut, 1970) have been observed in several species (Ouelette & Gagnon, 1960; Mariat & Diez, 1971). Occasionally sympodial conidiogenous cells are formed inside hyphal cells (Kendrick & Molnar, 1965).

A number of species are characterized by the presence of Graphium-like synnemata (Leptographium, Lagerberg & al., 1927; Scopularia, Goidànich, 1936c; Haplographium, Siemaszko, 1939; Coremiella, Georgescu & Orenski, 1957; Pesotum, Crane & Schoknecht, 1973). The conidia are formed by sympodial growth of the conidiogenous cell, leaving very inconspicuous scars at liberation (Crane & Schoknecht, 1973). In proportion to the development of the synnemata these fungi can be classified in Graphium Corda, Verticicladiella Hughes or Raffaelea v. Arx & Hennebert. The generic limits, however, are vague; this group of Hyphomycetes urgently needs to be revised. [p. 5]

The perfect states of the present species have hitherto been classified in Ceratocystis Ellis & Halst. A discussion on its taxonomy is presented on p. 16.

 

Classification. In the genera concerned there is a considerable diversity in the rate of differentiation in each species. Some are characterized by a complicated system of fertile branches, but have a relatively simple process of conidium formation. Others have rather inconspicuous conidiophores, but their conidial production is very peculiar. The majority of the species have a rather simple overall structure. The classification of such a variety of shapes is the intuitive intellectual activity of the taxonomist. The results of his thinking are difficult to verify without re-examination of the elaborated materials. Any given group of organisms can be arranged in several ways; many a possible hierarchy can be displayed, each depending on the operational views, feelings or needs of the arranger. In taxonomy this absence of a guideline sometimes becomes a persistent source of error and controversy. Therefore numerous taxonomists have felt the need to show how they arrive at their classification so as to make the ‘irrationality’ of their classifying comprehensible.

Broadly speaking, this has now lead to two dissimilar trends in fungal taxonomy. Firstly, by means of statistical analyses of features and properties, taximetry yields highly valuable results when series of equivalent OTU’s (Operational Taxonomic Units) are used (Morgan, 1971a and b; Shechter & al., 1972).On the other hand traditional taxonomy becomes more and more phylogenetically orientated. Both trends are hard to compare, since they operate on different levels. For confirmation of arrangements of genera and families which hitherto have been classified on the basis of only few — but ‘important’, i.e., with a supposed phylogenetic background — characteristics, neo-Adansonian methods are highly unsuitable (Kendrick & Weresub, 1966). Accordingly it will be impossible to order the diversity of life optimally by means of a single method, as can be done with dead objects. Each group requires another approach, and modifications of the methods effective at higher levels will often be inevitable. For instance, bacterial classification is different from that of Primates. Classification of Sporothrix and allied form-genera is purely phenetic, whereas taxonomy of Ceratocystis should comprise the total life-cycle.

In the present fungi the most practical arrangement of species appeared to be in genera each distinguished by a diagnostic character: in Blastobotrys the process of conidium formation is peculiar, Sporothrix has conidium-bearing denticles, Calcarisporiella gen. nov. has conidiogenous cells of an unusual shape, and Calcarisporium can be recognized by verticillate conidiophores. This phenetic classification can be demonstrated by com­paring differentiation of the fertile supporting structures with the part of the organism which is directly involved in the conidial production. In this sense the supporting structures comprise fertile hyphae and basal parts of the conidiogenous cells, whereas the conidiogenous structures concern the shape of the conidium-bearing protrusions and conidia. [p. 6]

 

 

Table 1. Subjective estimation of characteristics in 5 genera of Hyphomycetes; for explanation see text. In the type species ofthe genera concerned, diagnostic combinations of characters are encircled. [p. 7]

 

Using the species as taxonomic units, each character which has been found sufficiently stable to be of any practical value is estimated individually according to a graduated scale, ranging from 0 to 9. The highest degree of differentiation is subjectively estimated as 9, no differentiation as 0(-). For instance, the rate of differentiation of conidiophores is maximal (9) inCalcarisporium arbuscula, intermediate (4) in Blastobotrys nivea, minimal(-)in Sporothrix schenckii; the projection of conidium-bearing denticles is maximal (9) in Calcarisporiella gen. nov., and very small (I) in Sporothrix fungorum. Thus, in the table and resulting diagram (Fig. 3), the reasons for the present choice of hierarchy have been displayed and can be criticized directly.

 

 

Fig. 3. Scatter-diagram of some genera of hyaline species with sympodial conidium formation. For explanation see text.

 

It is needless to say, however, that this visualizing method has been designed [p. 8] and is suitable merely for the present group of Hyphomycetes. In general, similar subjective methods can be useful only for comparison of small numbers of OTU’s.

 

 

 KEY TO THE SPECIES DESCRIBED IN THE PRESENT PAPER

 

1.

Erect, verticillate conidiophores present

Calcarisporium arbuscula

1.

Conidiophores, if differentiated, not verticillate

2

 

 

 

2

Conidiogenous cells consisting of an inflated basal part and a filiform neck, apically with long, cylindrical denticles

Calcarisporiella thermophila

2

Conidiogenous cells of other shape

3

 

 

 

3

 Conidiiferous rachis remotely geniculate, denticulate; conidia globose, forming small, globose secondary conidia

Blastobotrys nivea

3

Not combining above characters

4

 

 

 

4

 Secondary conidia absent or very rare

5

4

 Secondary conidia abundant

23

 

 

 

5

Conidia conspicuously curved

6

5

Conidia straight; a small percentage of the conidia may be flattened at one side

8

 

 

 

6

 Conidia narrowed at the base; conidiogenous cells elongate, gradually tapering towards the tip

Sporothrix curviconia

6

Conidia reniform or allantoid; conidiogenous cells irregularly cylindrical

7

 

 

 

7

Colonies hyaline or greyish; conidiogenous cells mostly about 8‑13 µm long

Ophiostoma microsporum

7

Colonies yellowish; conidiogenous cells mostly about 10-30 µm long

Sporothrix luteoalba

 

 

 

8

Conidium-bearing denticles large, occurring scattered in the apical region of the conidiogenous cell; entomogenous species

Sporothrix ghanensis

8

Not combining above characters

9

 

 

 

9

Conidia formed on a more or less elongate, denticulate conidiiferous rachis

10

9

Conidia formed on an apical, restricted cluster of denticles

16

 

 

 

10

Conidiogenous cells broadly cylindrical

Ophiostoma nigrocarpum

10

Conidiogenous cells elongate, acicular to filiform

11

 

 

 

11

Conidiiferous rachids with a few, scattered, small denticles

Ophiostoma epigloeum

11

Conidiiferous rachids with numerous, densely crowded, conspicuous denticles

12

 

[p. 9]

 

12

Conidiiferous rachis often nodose; conidia guttuliform

Sporothrix insectorum

12

Conidiiferous rachis not nodose; conidia fusiform

13

 

 

 

13

 Conidiogenous cells firm, widest near the base, tapering towards the tip, with a well differentiated denticulate rachis; ambrosia‑fungi

14

13

 Conidiogenous cells fragile, of equal width throughout; rachis not differentiated from the basal part; entomogenous fungi

15

 

 

 

14

 Conidia 4-6 m long; Graphium-like conidial state usually present; colonies with a yellowish reverse

Ophiostoma ulmi

14

Conidia 5-10 µm long; Graphium-like conidial state absent; colonies with a brown reverse

Ophiostoma piliferum

 

 

 

15

Conidia usually 6.5-8.5µm long

Sporothrix alba

15

Conidia usually 3.5-4.5 µm long

Sporothrix isarioides

 

 

 

16

Conidiogenous cells short, more or less cylindrical

17

16

Conidiogenous cells of other shape

18

 

 

 

17

Conidiogenous cells irregular, with scattered denticles

Ophiostoma nigrocarpum

17

Conidiogenous cells regular, with an apical, inflated cluster of denticles

Sporothrix foliorum

 

 

 

18

Conidiogenous cells usually dichotomously or irregularly branched, often becoming septate in the basal part

Sporothrix ramosissima

18

Conidiogenous cells unbranched

19

 

 

 

19

Fragile species, parasitizing Meliolaceae

Sporothrix setiphila

19

 On other substrata

20

 

 

 

20

Species occurring on Narcissus bulbs

Ophiostoma narcissi

20

On other substrata

21

 

 

 

21

Conidiogenous cells regular, apically with a conspicuously swollen head with denticles; brown, globose lateral conidia abundant; colony reverse blackish

Sporothrix inflata

21

Not combining above characters

22

 

 

 

22

Verticicladiella-like state present in fresh cultures

Ophiostoma tetropii

22

Verticicladiella-like state absent

Sporothrix schenckii

 

[in pure culture usually indistinguishable from the conidial state of Ophiostoma stenoceras (13)]

 

 

 

 

23

Conidiogenous cells wide, regularly cylindrical or nearly so; colonies when young white, powdery or velvety

24

23

Conidiogenous cells usually narrower, more irregular or tapering conspicuously; colonies, if white, flocculose or lanose

25

 

 

 

24

Secondary conidia globose, much smaller than the primary conidia

Sporothrix fungorum

24

Secondary conidia guttuliform, often in short chains and only little smaller than the primary conidia; usually a conspicuous purple agar-pigment is formed

Sporothrix cyanescens

 

[p. 10]

 

25

Conidiogenous cells of irregular shape, usually with an elongate, irregular rachis

Ophiostoma longirostellatum

25

Conidiogenous cells elongate, regular, with an apical cluster of conidium-bearing denticles

26

 

 

 

26

Denticles small, arising in a small number at the tips of acicular conidiogenous cells; fertile hyphae often fasciculate

Ophiostoma perfectum

26

Not combining above characters

27

 

 

 

27

Graphium-like synnemata present, at least in fresh cultures

Ophiostoma picea

27

Graphium-like synnemata absent

see Ophiostoma populinum, O. multiannulatum

 

 

 blastobotrys v. Klopotek

 

Blastobotrys v. Klopotek — Arch. Mikrobiol. 58: 92. 1967.

 

Colonies growing slowly, appearing farinose, white. Vegetative hyphae hyaline, smooth- and thin-walled, forming a compact mycelium. Conidio­phores hyaline, smooth- and thin-walled, erect, solitary and little branched, imperceptably merging into the vegetative mycelium. Conidiogenous cells integrated, slightly tapering towards the tip; conidiiferous rachis geniculate, denticulate. Conidia blastic, hyaline, one-celled, smooth- and thin-walled; primary conidia globose to obovoidal; secondary conidia arising more or less synchronously, globose. No chlamydospores or perfect state were observed.

 

Descriptions are based on colonies growing on 2% malt agar at 35ºC.

 

Type species: Blastobotrys nivea v. Klopotek

 

 

1 Blastobotrys nivea v. Klopotek — Fig. 4

 

Blastobotrys nivea v. Klopotek — Arch. Mikrobiol. 58: 92. 1967.

 

Colonies in vitro attaining a diameter of 14 mm in 10 days, appearing farinose, somewhat raised and folded in the centre, compact, up to 3 mm high, white. Reverse cream coloured. Exudate and odour absent. Vegetative hyphae hyaline, smooth-walled, (1.2-)2-3 µm wide, often slightly undu­lating, forming a compact mycelium or occasionally a more or less hymeniform layer. Conidiophores hyaline, smooth-walled, fragile, usually about 1.5 µm wide at the tip, up to 230 µm high, slightly widening towards the base, erect, mostly solitary and little branched, imperceptably merging into the vegetative mycelium. [p. 11]

 

 

Fig. 4. Blastobotrys nivea, CBS 163.67. a. conidiophores; b. detached conidia. [p. 12]

 

Conidiogenous cells integrated; conidiiferous rachis regularly geniculate, denticulate; denticles blunt, nearly as wide as the rachis, about 1.5 µm long, at distances of 3-6 µm (up to 50 µm). Conidia hyaline, smooth- and thin-walled; primary conidia globose to obovoidal, 2.5-4.5 µm wide, with a short basal stalk, mostly with numerous scars of secondary conidia; secondary conidia globose, 2-2.5 µm in diameter, formed more or less synchronously, remaining attached to the primary conidia long after maturation. No chlamydospores were observed. Perfect state unknown.

 

Material examined

 

CBS 163.67 (= ATCC 18420), type culture, isolated from compost, Heidelberg, W-Ger­many, 1967.

 

Discussion

 

Blastobotrys is characterized by suberect, rather well differentiated conidiophores, apically with a denticulate, strongly geniculate conidiiferous portion. Usually the stalk of the conidiophore becomes septate only after maturation of a series of primary conidia; consequently the conidiogenous cells are integrated.

The secondary conidia are initiated shortly after each other and have a rather long period of maturation. Thus mostly several secondary conidia are ripening on the same primary conidium. The terms ‘synchronous’ or ‘serial’, as defined by Kendrick (1972) do not exactly fit this process of conidium formation.

Optimal growth of Blastobotrys nivea occurs at 30-35°C (Fig. 5). After 10 days no growth was observed above 45°C and below 50C.

 

 

 Sporothrix Hektoen & Perkins ex Nicot & Mariat

 

Sporothrix Hektoen & Perkins — J. exp. Med. 5: 77. 1900 (without diagnosis); ex Nicot & Mariat — Mycopath. Mycol. appl. 49: 61. 1973.

Sporotrichopsis Gueguen in de Beurmann & Gougerot — Archs Parasit. 15: 104. 1911 (nomen provisorium).

 

Colonies growing moderately slowly, appearing smooth, farinose, floccose or lanose, white or hyaline, later often greyish to black, sometimes purplish or yellowish. Submerged hyphae hyaline, smooth- and thin-walled; aerial hyphae, if present, loose or sometimes fasciculate. Conidiogenous cells scattered, arising from undifferentiated hyphae, cylindrical to linear, apically with a cluster of conidium-bearing denticles, or with a rather [p.13] irregular, denticulate rachis. The conidiogenous cell often proliferates at or somewhat below the apex and gives rise to another cluster of denticles or a conidiogenous cell, which in turn may become intercalary. Sympodial conidia hyaline, one-celled, smooth- and thin-walled, subglobose to fusi­form, basally pointed or with a small hilum; lateral conidia, if present, brownish, one-celled, smooth- and usually rather thick-walled, globose to fusiform. No chlamydospores were observed. Perfect state: Ophiostoma H. & P. Syd. (=Ceratocystis auctt. p.p.)

Descriptions are based on colonies growing on oat-meal agar at 20°C.

 

Type species: Sporothrix schenckii Hektoen & Perkins

 

 

Fig. 5. Effect of temperature upon mycelial growth of Blastobotrys nivea (dotted line) and Calcarisporiella thermophila (straight line).

 

 

 

Discussion

 

Nomenclature. A representative of the genus was first mentioned by Schenck (1898) as Sporotrichum sp. A second isolate was described by Hektoen & Perkins (1900) as a new species, Sporothrix schenckii. The new [p. 14] generic name was only mentioned in the title of the article. Both Sporo­trichum’ and ‘Sporothrix’ have the same meaning in Latin (spore hair), so Müller (1965) suspected that Hektoen & Perkins might not have intended to erect a new genus. Indeed they did not provide a generic diagnosis. According to art. 32 of the International Code of Botanical Nomenclature the name Sporothrix was published invalidly.

Sporotrichopsis [type species: S. beurmannii (Matr. & Ramond) Gueguen] was invalidly published as a nomen provisorium. Dolichoascus Thibaut & Ansel (type species: D. schenckii Thibaut & Ansel in Ansel & Thibaut) was described as the perfect state of Sporothrix schenckii. However, according to Mariat & Diez (1971) the endoconidia of Sporothrix schenckii, which can be observed rather frequently in 4-months-old cultures in liquid media, were concerned. As a consequence the name Dolichoascus can not be used for a form-genus of species with sympodial conidium for­mation.

For above reasons the name Sporothrix was validated by Nicot & Mariat (1973).

 

Delimitation. The form-genus Sporothrix is characterized by hyaline, elongate conidiogenous cells, which arise from undifferentiated hyphae, and form hyaline, one-celled conidia on distinct denticles, by sympodial growth of their tips. If occasionally fertile hyphae are somewhat differentiated, the conidiogenous cells are integrated.

Calcarisporiella gen. nov. is very similar to Sporothrix, but is separated because of the properties of the conidiiferous rachids and the shape of the conidiogenous cells. On the natural substrate and in freshly isolated cultures Calcarisporium Preuss is easily recognizable by the erect conidiophores; after some transfers, however, it often differs from Sporothrix merely by the length of the conidium-bearing denticles and the frequent occurrence of verticillate branching.

Blastobotrys is closely related to Sporothrix fungorum de Hoog & de Vries, but differs by the peculiar shape of the conidiogenous cells. Sporothrix fungorum is also similar to some species of Trichosporon Behrend, e.g. the conidial state of Pichia burtonii Boidin & al.; the latter differs by the absence of distinct conidium-bearing denticles. Hyalodendron Diddens and Sympodiomyces Fell & Statzell are close to Sporothrix, but in these genera the conidiogenous cells are not differentiated and form conidia on inconspicuous scars at their tips; the conidia usually form secondary conidia or conidiophores. The conidial state of Cephaloascus fragrans Hanawa is also closely related. The conidia are formed in short chains, which are borne on conspicuous denticles at the tips of short, clavate conidiogenous cells. Unlike Sporothrix, these cells usually become detached. There is much similarity with some species of Ramularia Unger, e.g. R. deusta (Fuck.) Baker & al. [ = Hyalodendron album (Dowson) Diddens; Baker & al., 1950]; this species is distinct due to darkened conidial scars and verru­cose conidia. Myceliophthora Cost. (von Arx, 1973a) has small, inflated conidiogenous cells, giving rise to a small number of chains of conidia. [p. 15]

Isaria sensu str. and Beauveria Vuill. are distinct, i.a. owing to the branching pattern and the shape of the conidiogenous cells. Beauveria alba resembles Sporothrix insectorum sp. nov., but has a long, regularly geniculate conidiiferous rachis and orthotropically branched fertile hyphae.

Numerous genera with multi-celled conidia formed on denticles have been described; some of them have representatives which have one-celled conidia, or which are reminiscent of Sporothrix by the shape of the conidiogenous cells. Pseudobotrytis bisbyi Timonin is distinct by the morphology and pigmentation of the conidiophore. Dactylaria lanosa Malla & W. Gams (1971) has large, spinous denticles and fusiform, two-celled conidia. Denticularia modesta (Syd.) Deighton (1972) slightly resembles S. ghanensis sp. nov., but is distinct due to subhyaline, catenulate conidia and conidiophores which are aggregated in tufts. Sympodiophora meliolae (Stev.) Deighton & Pirozynski (1972) has also some characteristics in common, but can easily be distinguished by the shape of the conidia and by the remotely denticulate, septate conidiophores. Eriomycopsis minuta Deighton & Pirozynski (1972) has two-celled, fusiform conidia, arising in a small number from subulate conidiogenous cells. Some species with two-celled conidia resembling Sporothrix even more, have been described, e.g. Sporotrichum niveum Kobayashi, S. hokkaidoense Kobayashi (Müller, 1965) and Verticillium vizei Berk. & Br. (MANCH, PAD). These species, however, are incompletely known from herbarium material or from literature only; their taxonomic position can not be ascertained.

Dexhowardia Taylor, and the microconidial state of Riessia semiophora Fres. (Goos & Tubaki, 1973) are distinct due to the conidia, which arise synchronously in a limited number at the tip of the conidiogenous cell.

Verticicladiella Hughes, Raffaelea v. Arx & Hennebert and Graphium auctt. are closely related genera, which can be distinguished from Sporo­thrix by the broad, rounded or truncate conidial bases, leaving only in-conspicuous scars when the conidia become detached. In Ophiostoma ulmi (Buisman) Nannf. both a Graphium-like and a Sporothrix conidial state occur, which sometimes are distinguished with difficulty. Pesotum Crane & Schoknecht (1973) was described to accomodate Graphium-like fungi with sympodial conidium formation. In the generic diagnosis the Sporothrix states of these species were described as well; consequently Pesotum is partially a synonym of Sporothrix. Chrysosporium Corda and Scedo­sporium Sacc. have conidia with broad bases and lack distinct denticles. The conidial states of some Microascaceae and Pseudeurotiaceae, referred to as Sporotrichum (Barron & al., 1961a, b), Beauveria (Booth, 1961) and Sporothrix (Malloch, 1970) can not be classified in Sporothrix because of the rounded conidial bases and the absence of denticles.

Rhinocladiella Nannf., Dicyma Boul., Hansfordia Hughes and Acrodon­tium de Hoog differ from Sporothrix by their rather thick-walled and pigmented conidiogenous cells and the subhyaline conidia. Pale cultures of Acrodontium salmoneum de Hoog may resemble Sporothrix insectorum, but can be distinguished by the properties of the conidiiferous rachids. Sporothrix ramosissima sp. nov. is reminiscent of some species of [p. 16] Nodulisporium Preuss; it is classified in Sporothrix on the basis of the hyaline mycelium and the integrated conidiogenous cells.

 

The perfect state. A number of Sporothrix species are known to have a perfect state, which usually has been classified in Ceratocystis. A concise treatment of the taxonomic history of this genus was given by Hunt (1956).

At present Ceratocystis is heterogenous, both in perfect and imperfect states. Over 80 species are known, in which 4 different types of ascospores occur, while the conidial states, if present, can be classified in at least 6 genera of Hyphomycetes. Various authors have tried to split the genus, and often arrived at diverse conclusions; their results are discussed below.

Nannfeldt (in Melin & Nannfeldt, 1934) created two sections: the species of sect. Brevirostrata Nannf. should have short, conical perithecial necks, whereas those of sect. Longirostrata should be characterized by longer, filiform necks. Three species were mentioned as typical species of the former section, which were all listed by Hunt (1956) as synonyms of Ceratocystis minor (Hedgcock) Hunt. The other section comprised the great majority of the genus. The value of perithecium-morphology as a taxonomic criterium is, however, doubtful. The shape and length of the perithecial necks may be extremely variable, mainly depending on environ­mental conditions (Rohde, 1936; Wright & Cain, 1961; Griffin, 1968; von Arx, 1973b). For instance, in a number of strains maintained in the CBS-collection, a rather high incidence of perithecia with conical or even papilliform necks was observed. Moreover some recently described, quite distinctive species of Ceratocystis, e.g. C. seticollis Davidson, C. brun­neocritina Wright & Cain and C. falcata Wright & Cain, are also characterized by perithecia with short, cylindrical or papilliform necks; in C. europhioides, when cultivated on Leonian’s agar, the necks may even be absent. For similar reasons Europhium Parker, the nonostiolate counterpart of Ceratocystis auctt., is enlisted here into synonymy.

The inner cell layers of young perithecia collapse during maturation to form a central cavity (Andrus & Harter, 1933); in a similar way the channel through the neck is formed (Sartoris, 1927). In most species of Ceratocystis the asci occur scattered throughout the cavity in crude, proliferating chains (Luttrell, 1951, and others). Fasciculate arrangement of broadly clavate asci is reported by Wright & Cain (1961) in C. europhioides. Francke-Grosmann (1953) thought the asci in Ceratocystis ips (Rumbold) C. Moreau arise from a conic substratum on the bottom of the perithecium, whereas in C. penicillata (Grosmann) C. Moreau they should occur throughout the perithecial cavity. The arrangement of the asci might very well be an aid in classification; at present, however, relevant data are still too scattered and too contradictory to be of any value yet.

Regarding the shape of the ascospores, there are in Ceratocystis basically four types, viz. cylindrical, ellipsoidal, reniform and falcate. The spores are expelled from the perithecia in a mucous medium; in many species a slime sheath is visible on each single spore. The sheath may be of various [p. 17] dimensions: it may be attached to one side of the spore as a narrow brim, and it may envelope the spore equally, or unequally, having acute ends at the edges of the spore. The above mentioned characters appeared to be of much practical value for the keys to the species given by Hunt (1956)and Griffin (1968). However, it is impossible to group the species of Cerato­cystis according to the characters of the ascospores only. In species without a slime sheath the spores range gradually from reniform via ellipsoidal to cylindrical. Similar gradations occur in the outlines of spores with slime sheaths. Only the species with falcate ascospores, e.g. C. minuta (Siemaszko) Hunt, form a rather well delimited group. In most of these species the perithecia are, partly or as a whole, rather pale; though the latter character is also found in quite different species, e.g. C. seticollis Davidson and C. alba DeVay & al., and pale as well as brown perithecia are reported in C. radicicola (Bliss) C. Moreau (El-Ani et al., 1957), it might be a valuable additional characteristic.

Spencer & Gorin (1971) subdivided Ceratocystis into 11 groups on account of the polysaccharide compounds of the cell-walls. Several of these groups reflect the morphological similarities remarkably well. Important research on cell-walls was also done by Smith et al. (1967);no doubt in future chemical data will be an important aid in classification.

Ceratocystis species with a Verticicladiella conidial state were accomo­dated by Goidànich (1936c) in Grosmannia. The usefulness of this classification was doubted by Siemaszko (1939), who pointed at the vague generic limits between Verticicladiella and Graphium. For that reason Hunt (1956)and Mathiesen-Käärik (1960) combined the species with Verticicladiella and Graphium states in ‘Section 2’. Their ‘Section 3’ comprised species with mycelial conidia only. Actually these species have poorly developed Verticicladiella- or Raffaelea-like conidial states. In several species, besides a Sporothrix conidial state a Graphium state occurs; occasionally the differences between species (e.g. C. piceae and C. populina, compare p. 59)is merely based upon the presence or absence of such a state. As a conse­quence, sectioning the sympodulosporous group is impossible.

Münch (1907) described Endoconidiophora for species with conidial states belonging to Chalara and similar genera. Hunt (1956) and Mathiesen-Käärik (1960)used the characters of the conidial states only for their broad sectioning within Ceratocystis, whereas Nannfeldt (in Melin & Nannfeldt, 1934) gathered species with all kinds of conidial states in the sect. Longirostrata. In the polemics that followed, the justness of a genus based on the characteristics of the conidial states only was the central question. To find an answer to this question, the relationships of both groups of species concerned should be taken into consideration.

Morphologically there is much similarity between Ceratocystis auctt. and some Eurotiales, e.g., Microascus Zukal (Nannfeldt, 1930; Parker, 1957). Recently Cain (1972) suggested a possible relationship with Cephaloascus Hanawa. In Cephaloascus the asci are formed in chains on erect ascophores, very similar to the conidiophores of the Verticicladiella state of Europhium aureum Robinson-Jeffrey & Davidson; besides a Sporothrix-like conidial [p. 18] state is present. This would be explained by the hypothesis that the peri­thecial state of a Ceratocystis-like ancestor would be lost, its function being taken over by the conidiophores. Similar deficiencies are found in the microcycli of some Uredinales; e.g., in Endophyllum sempervivi (Alb. & Schw.) de Bary the teleutospores are lost and the basidia are formed on the aecidiospores. As a consequence of this theory the Ceratocystis species with sympodial conidial states would be more closely related to Cephaloas­cus than those with Chalara-like conidial states. This would justify a separation of the present groups, which can be defined as follows:

 

 

Ceratocytis Ellis & Halst. — Bull. New Jers. agric. Exp. Stn 76: 14. 1890.

 

Rostrella Zimmermann — Meded. Lds PlTuin, Batavia 37: 24. 1900 (non Fabre — Annls Sci. nat., Scr. 6, 9: 66. 1878).

Endoconidiophora Munch — Naturw. Z. Forst- u. Landw. 6: 564. 1907.

Ophiostoma H. & P. Syd. section Longirostrate Nannf. pro parte — Svenska SkogsvFör. Tidskr. 32: 407. 1934.

 

Perithecia single or in clusters, consisting of a pale or dark brown, globose base, provided with a stiff, cylindrical or filiform, blackish neck. Paraphyses absent. Asci evanescent, globose to broadly clavate, 8-spored. Ascospores hyaline, small, smooth- and thin-walled, ellipsoidal to slightly reniform or crescent-shaped, often with a mucous brim at one side, thus being hat- or crescent-shaped in outline. Conidial states: Chalara, Chalaropsis, Thielaviopsis.

 

Type species: Ceratocystis fimbriata Ellis & Halst. in Halst.

 

List of accepted species (general references: Hunt, 1956):

 

Ceratocystis adiposa (Butler) C. Moreau
References:
Butler (1906, as Sphaeronaema adiposum), Sartoris (1927, as Ceratostomella adiposa), Davidson (1935, as Endoconidiophora adiposa).

 

Ceratocystis autographa Bakshi
Reference: Bakshi, 1951b.

 

Ceratocystis coerulescens (Munch) Bakshi
References: Munch (1907, as Endoconidiophora
coerulescens), Lagerberg et al. (1927, as Endoconidiophora coerulescens), Siemaszko (1939 as Ophiostoma coerulescens f. douglasii), Bakshi (1951a), Kessler & Anderson (1960), Griffin (1968).

 

Ceratocystis fagacearum (Bretz) Hunt
References: Henry (1944, as Chalara
quercina), Bretz (1951, as Chalara quercina, 1952, as Endoconidiophora fagacearum), Curl et al. (1953), [p. 19] Stessel & Zuckerman (1953) and Wilson (1956), all as Endoconidiophora fagacearum.

 

Ceratocystis fimbriata Ell. & Halst. in Halst.
References: Halsted & Fairchild (1891), Zimmermann (1900, as Rostrella coffeae), Elliott (1925), Harter & Weimer (1929) and Andrus & Harter (1933, all as Ceratostomella fimbriata), Davidson (1935, as Endoconidiophora fimbriata), Gwynn-Vaughan & Broadhead (1936) and Pontis (1951, as Ceratostomella fimbriata), von Arx (1952, as Ophiostoma coffeae), Chevaugeon (1957), Morgan-Jones (1967).

 

Ceratocystis major (van Beyma) C. Moreau
References: van Beyma (1935, as Ceratostomella major), C. Moreau (1952).

 

Ceratocystis moniliformis (Hedgcock) F. Moreau
References: Davidson (1935, as Endoconidiophora moniliformis), Andrus & Harter
(1937, as Ceratostomella moniliformis), Bakshi (195a, as Cera­tocystis wilsonii), F. Moreau (1952), Luc (1952, with several formae speciales), Morgan-Jones (1967).

 

Ceratocystis musarum Riedl
Reference: Riedl (1961). Probably identical with
C. paradoxa (Dade) C. Moreau.

 

Ceratocystis paradoxa (Dade) C. Moreau
References: Dade (1928, as Ceratostomella paradoxa), Davidson (1935, as Endoconidiophora paradoxa), Joly (1961, as Thielaviopsis paradoxa), Robertson (1962), Morgan-Jones (1967), Cole & Kendrick (1969).

 

Ceratocystis radicicola (Bliss) C. Moreau
 
Reference: Bliss (1941, as Ceratostomella radicicola).

 

Ceratocystis variospora (Davidson) C. Moreau
Reference: Davidson (1944, as Endoconidiophora variospora).

 

 

Ophiostoma H. & P. Syd. — Annls Mycol. 17: 43. 1919.

 

Linostoma v. Höhn. — Annls Mycol. 16: 91. 1918 (not Wall. — num. Cat. East Indies Comp., London. 1828).

Ophiostoma H. & P. Syd. section Longirostrata Nannf. pro parte — Svenska SkogsvFör. Tidskr. 32: 407. 1934..

Ophiostoma H. & P. Syd. section Brevirostrata Nannf. — Svenska SkogsvFör. Tidskr. 32: 407. 1934.

Grosmannia Goidànich — Boll. Staz. Patol. veg. Roma 16: 26. 1936.

Europhium Parker — Can. J. Bot. 35: 175. 1957.

 

Perithecia single or in clusters, consisting of a pale brown to black, globose base, provided with a straight or flexuose, filiform, cylindrical or papilliform, blackish or pale brown neck; occasionally nonostiolate. Paraphyses and periphyses absent. Asci evanescent, globose to broadly [p. 20] clavate, 8-spored. Ascospores hyaline, small, smooth- and thin-walled, cylindrical, ellipsoidal, reniform or falcate, often with a mucous sheath enveloping the spore partially or totally. Conidial states: Graphium, Sporothrix, Verticicladiella.

 

Type species: Ophiostoma piliferum (Fr.) H. & P. Syd.

 

 

Ophiostoma sensu str. comprises the great majority of former Ceratocys­tis species. Numerous species have been described and keyed out by Hunt (1956) and Griffin (1968); additional species have been described, e.g., by Wright & Cain (1961), Davidson (1966, 1971), Robinson-Jeffrey & Davidson (1968) and Butin & Zimmermann (1972).

 

 

Fig. 6. Sporothrix fungorum, CBS 508.72. a. conidial apparatus; b. formation of second­ary conidia.

 

 

2. Sporothrix fungorum de Hoog & de Vries — Fig. 6

 

Sporothrix fungorum de Hoog & de Vries — Antonie van Leeuwenhoek 39: 518. 1973.

 

Discussion

 

A full description and illustration of this species was given by de Hoog & de Vries (1973). Sporothrix fungorum is characterized by long, [p. 21] cylindrical conidiogenous cells and primary and secondary conidia which are rather well differentiated from each other.

The conidiogenous cells are formed on ascending hyphae. Young hyphae are remotely septate; within 48 hours some primary conidia are formed at their tips. Soon afterwards lateral branches are formed just below the septa, having sharp angles with the main stalk (Fig. 6a). During maturation of the conidia the main and lateral branches become more septate, and the conidiogenous cells integrate. In short lateral branches often no basal septum is formed.

Conidium ontogeny in S. fungorum resembles Blastobotrys nivea (de Hoog & de Vries, 1973). By means of time-lapse sequences it could be demonstrated that the conidiogenous cells give rise to series of large primary conidia by sympodial growth. Each primary conidium forms serially or more or less simultaneously several secondary blastoconidia. Often also tertiary conidia are formed. This type of conidium formation occurs also in Sporothrix cyanescens and numerous conidial states of Ophiostoma species, e.g. O. piceae (Münch) H. & P. Syd.

Optimal growth of Sporothrix fungorum occurs at 15-25ºC. No growth was observed in any of the strains after 10 days above 30°C; at 5°C some growth still occurred.

 

 

3. Sporothrix cyanescens de Hoog & de Vries

 

Sporothrix cyanescens de Hoog & de Vries — Antonie van Leeuwenhoek 39: 515. 1973..

 

Discussion

 

This species, described and depicted by de Hoog & de Vries (1973), resembles Sporothrix fungorum. It can be distinguished by the secondary conidia, which are guttuliform to fusiform, of about the same shape and size as the primary conidia, though usually somewhat smaller. Moreover many conidiogenous cells arise orthotropically from undifferentiated hyphae, and are rather short, not integrated in a side branch. In old cultures, some of the lateral conidiogenous cells are rather narrow, giving rise to a geniculate or irregularly bent conidiiferous part, resembling Beau­veria Vuill.

The production of the acidic-alkaline indicator pigment, as described by de Hoog & de Vries (1973) is not stable. The intensity of the pigment varies in different strains, and may be inconstant per strain under different conditions. Sometimes no pigment can be demonstrated at all.

Optimal growth of Sporothrix cyanescens occurs at 25-30°C. Above 35°C growth is rather slow, but at this temperature the sprouting of the conidia may be stimulated. At higher temperatures the colonies usually have a striking brain-like appearance. [p. 22]

 

 

Fig. 7. Sporothrix alba, from collection T. Petch. a. conidial apparatus; b. conidiogenous cells; c. conidia.

 

 

4. Sporothrix alba (Petch) de Hoog, comb. nov. — Fig. 7

 

Sporotrichum album Petch — Trans. Br. mycol. Soc. 11: 262. 1926 (basionym).

 

Mycelium on natural substrate forming a thin layer of hyaline hyphae, from which several cream coloured mycelial tufts arise, up to 3 mm high. Aerial hyphae hyaline, smooth-walled, 1.5-2.5 µm wide. Conidiogenous cells scattered, arising terminally or laterally from undifferentiated hyphae or integrated in short side branches, cylindrical, mostly about 50 µm long and 1.2-2.5 µm wide; apical part forming conidia by sympodial growth, consisting of a long, somewhat flexuose, denticulate rachis; denticles rather small, often blotch-like, usually less than 0.5 µm long. The conidiogenous cell often proliferates near the apex and gives rise to another conidiogenous cell, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, fusiform, with a pointed base, 6.5-8.5 x 1-1.5 µm. Perfect state unknown.

 

Material examined

 

Sporotrichum album in herb. Petch (K), type, covering Cordyceps dipterigena Berk. & Br. and a fly (Medaea sp.), Hakgala, Ceylon, March 1922. [p. 23]

Sporotrichum album in herb. Petch (K) no. R-298, R-313, R-329 and R-552, all on Cordyceps sp. and insects, Nuwara Eliya, Ceylon, 1927-28.

 

Discussion

 

At present the fungus is only known from dried herbarium material. Petch (1931a) tried to grow Sporotrichum album on oat-meal agar. It grew very scantily and coloured the agar chocolate brown, but did not produce conidia. The cultures have not been preserved.

In the dried material some conidia were observed with small scars or a short sympodial rachis near the base, which possibly had arisen after liberation.

 

 

Fig. 8. Sporothrix isarioides, from collection T. Petch. a. conidial apparatus; b. conidia.

 

5. Sporothrix isarioides (Petch) de Hoog, comb. nov. — Fig. 8

 

Sporotrichum isarioides Petch — Trans. Br. mycol. Soc. 16: 58. 1931 (basionym).

Sporotrichum columnare Petch — Trans. Br. mycol. Soc. 19: 186. 1935.

? Sporotrichum niveum Kobayasi — Bull. biogeogr. Soc. Jap. 9: 288. 1939 [non Sporotrichum niveum Allesch. & P. Henn. — Bibl. Botan., Stuttgart 42. 1897] =Didymobotryopsis nivea (Kobayasi) G. Muller — Wiss. Z. Humboldt-Univ., math.-nat. R. 14: 778. 1965.

 

 

Mycelium on the natural substrate forming a thin layer of hyaline hyphae, from which several white or cream coloured, cylindrical synnemata [p. 24] simple or branched; central axis about 100 µm wide, consisting of sterile, fasciculate hyphae, covered over the whole length with numerous fertile hyphae. Aerial hyphae hyaline, smooth-walled, 1.5-2.5 µm wide. Conidiogenous cells scattered, arising terminally or laterally from the outer hyphae of synnemata, sometimes integrated in short side branches, usually about 40 µm long and 1.2-2.5 µm wide; apical part forming conidia by sympodial growth, consisting of a long, somewhat flexuose, denticulate rachis; den­ticles pointed, rather small, mostly less than o.5 µm long. The conidiogenous cell often proliferates near the apex and gives rise to another conidiogenous cell, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, fusiform, with a pointed base, 3.5-5.5x 1.2-1.5 µm. Perfect state unknown.

 

Material examined

 

Sporotrichum isarioides in herb. Petch (K): no. R-301, R-307, R-308, R-311, R-331, R-332 and R-455,all covering Cordyceps dipterigena and a fly (Medaea sp.), Nuwara Eliya, Ceylon, 1927; R-377 on Calonectria sp. on leafhopper, Nuwara Eliya, Ceylon, 1928; unnumbered, on an ant, Krugala, Ceylon, coll. Q. C. Hutson.

Sporotrichum columnare in herb. Petch (K), covering Hirsutella floccosa Speare and a froghopper, Trinidad, coll. E. M. Wakefield.

 

Discussion

 

The fungus is only known from dried herbarium material. Petch (1931) tried to grow the fungus on oat-meal agar. It developed a continuous, pulverulent colony, with numerous short, erect, rather loose, cylindrical tufts. These cultures have not been preserved.

Petch (1931) did not select a holotype specimen. The collection of Sporothrix isarioides in K was not homogeneous: an unnumbered envelope contained a synnema of Beauveria brongniartii (Petch) Sacc. on the larva of Calandra sp. (Coleoptera); R-301 contained, apart from the meant fungus, a similar polyphialidic species. No. R-331, which contains well developed synnemata of Sporothrix isarioides, is selected here as lectotype specimen.

Of Sporotrichum columnare only one collection has been preserved. It did not comprise any synnemata. However, Petch (1935) mentioned in the diagnosis, based upon collections from four localities in tropical South-America, synnemata of 1.8 mm high and 0.3 mm wide.

Type material of Sporotrichum niveum was not available for study. According to the diagnosis the species differed from Sporothrix isarioides by the scarce occurrence of conidia with a transverse septum. Based upon this character Müller (1965) made a new combination in Didymobotryopsis P. Henn.; however, the type species of this genus, D. parasitica P. Henn. (B), has swollen, elongate conidiogenous cells with a narrow, geniculate, cicatrized rachis and cylindrical conidia. [p. 25]

Müller (1965) mentions a similarity with Beauveria petelotii Vincens. This species was considered as doubtful by de Hoog (1972).

Sporothrix isarioides is very similar to S. alba. It is distinct due to the presence of synnemata, and by the shape and size of the conidia. Possibly there are also differences in the properties of the species in pure culture (Petch, 1931).

 

 

Fig. 9. Sporothrix insectorum, from living cultures. a. conidial apparatus; b. conidia.

 

 

6. Sporothrix insectorum de Hoog & Evans, sp. nov. — Fig. 9

 

Coloniae in vitro post 10 dies 8mm diametro, lanosae, ad 3 mm altae, hyalinae. Reversum cremeum. Hyphae hyalinae, glabrae. Cellulae conidiogenae in hyphis non differentiatis laxe oriundae; plerumque circa 40 µm longae et 1.2-2 µm latae; pars apicalis incremento sympodiali conidia formans, ex rachi longa, plerumque nodosa-denticulata consistens; denticuli pustuliformes. Conidia hyalina, glabra vel rugulosa, guttuliformia ad fusiformia, (3.1-)4-6 x 1.8-2.5 µm. Status perfectus ignotus.

Typus CBS 756.73, sub numero 45, Mt Atewa, Ghana, ab H. C. Evans missus.

 

Colonies in vitro attaining a diameter of 8 mm in 10 days appearing lanose, up to 3 mm high, white. Reverse cream coloured. Some hyaline exudate may be present; odour absent. Submerged hyphae hyaline, smooth-walled, 1.5-3.5 µm wide. Aerial hyphae hyaline, smooth-walled, 1.2-2.5 µm wide, ascending. Conidiogenous cells scattered, arising plagiotropically from undifferentiated hyphae or from short side branches, often also in terminal position, usually about 40 µm long and 1.2-2 µm wide; apical part [p. 26] forming conidia by sympodial growth, consisting of a long, usually nodose, somewhat flexuose denticulate rachis; denticles blotch-like, mostly less than 1.5 µm long. Occasionally the conidiogenous cell becomes intercalary by proliferation. Conidia hyaline, smooth- or slightly rough-walled, guttuliform to fusiform, with a pointed base, (3.2-)4-6 x 1.8-2.5 µm. Perfect state unknown.

Mycelium on the natural substrate consisting of scattered, simple synne­mata, arising from body openings of the insect, up to 2 mm high; stalk sterile, up to 0.2 mm wide, terete, tomentose when young, later glabrous and horny, brownish; head composed of loose, hyaline fertile hyphae. Some hyaline arachnoidal mycelium may be present on the surface of the insect.

 

Material examined

 

Herbarium specimens

 

Samson no. 0015, on Paltothyreus tarsatus on Rubiaceae, associated with Gibellula formi­carum Mains, Mt Atewa, Ghana, coll. H. C. Evans, January 1972. Samson no. 0017, on Paltothyreus tarsatus on Rubiaceae, Begoro, Ghana, coll. H. C. Evans, December 1971.

 

Living strains

 

CBS 756.73, type culture, sent by H. C. Evans under no. 45, Mt Atewa, Ghana, January 1973..

CBS 770.73 isolated by H. C. Evans under no. 28 from Paltothyreus tarsatus, associated with Torrubiella sp., Mt Atewa, Ghana, January 1973..

CBS 771.73 isolated by H. C. Evans under no. 64 from Cercopidae, Kukurantumi, Ghana, January 1973..

CBS 858.73 isolated by H. C. Evans under no. 27-E from Paltothyreus tarsatus on rotten log, associated with Torrubiella sp., Mt Atewa, Ghana. July 1972.

 

Discussion

 

In pure culture locally abundant sporulation occurs, showing the characteristic nodose conidiiferous rachids, which are also very common on the natural substrate. No synnemata were formed on artificial media.

Sporothrix insectorum resembles S. isarioides. It can be distinguished by its firm conidiogenous cells with nodose conidiiferous rachids, and by the conidia, which usually are wider, often guttuliform to subglobose. The conidial state of Ophiostoma piliferum is also reminiscent, but differs by the greyish brown colonies and the long denticulate, not nodose conidii­ferous rachis. [p. 27]   

 

 

Fig. 10. Sporothrix ghanensis, CBS 755.73. a. conidial apparatus; b. conidia.

 

 

7. Sporothrix ghanensis de Hoog & Evans, sp. nov. — Fig. 10

 

Coloniae in vitro post 10 dies 4-7 mm diametro, recentes fasciculatae, vetustiores lanosae; primum hyalinae, deinde pallide citrinae ad sulphureae. Reversum pallide purpureum. Hyphae hyalinae, glabrae. Cellulae conidiogenae in hyphis non differentiatis (axe oriundae, plerumque circa 30 µm longae et 1.5-3.5 µm  latae; pars apicalis incremento sympodiali conidia formans, ex rachi flexuosa, irregulari consistens, denticulis laxe dispositis praedita; denticuli acuminati vel cylindracei. Conidia hyalina, glabra vel rugulosa, guttuliformia ad clavata, (4.5-)5.5-7.5(-10.5) x 2.8-3.3 µm. Status perfectus ignotus.

Typus CBS 755.73, ex aranea ovigerente in folia Theobroma cacao L., Tafo, Ghana, ab H.C. Evans sub numero 18-E isolatus.

 

Colonies in vitro attaining a diameter of 4-7 mm in 10 days, forming in fresh isolates a dense mycelial mat with some small synnemata up to 3 mm high, after some transfers becoming lanose, with cushion-like tufts of mycelium; at first white, later becoming pale citron yellow to sulphur yellow. Reverse purplish; on 2% malt agar wine red. Exudate and odour absent. Submerged hyphae hyaline, smooth-walled, 1.3-3 µm wide, often forming a compact mycelium. Aerial hyphae hyaline, smooth-walled, 1.5-3 µm wide. Conidiogenous cells scattered, arising terminally or laterally from undifferentiated hyphae or integrated in short side branches, usually about 30 µm long and 1.5-3.5 µm wide; apical part forming conidia by sympodial growth, consisting of a flexuose, irregular rachis, not differentiated [p. 28] from the basal part, with scattered denticles; denticles pointed or cylindrical, usually about 1 µm long, up to 3.5 µm. Conidia hyaline, smooth- or slightly rough-walled, guttuliform to clavate, basally with a scar, (4.5-)5.5-7.5(-10.5) x 2.8-3.3 µm. Perfect state unknown.

Mycelium on the natural substrate consisting of long, slender synnemata creeping radially over the leaf surface, terminating in small fertile heads composed of loose mycelium.

 

Material examined

 

Herbarium specimen

 

Samson no. 0087, on spider with eggs on leaf of Theobroma cacao L.., Tafo, Ghana, coll. H. C. Evans under no. 18-E.

 

Living strains

 

CBS 755.73, type culture, isolated by H. C. Evans under no. 18-E. CBS 769.73 sent by H. C. Evans under no. 4.

 

Discussion

 

The collection on the natural substrate, especially the synnematal heads, was heavily overgrown with a Sympodiophora species.

Sporothrix ghanensis can be distinguished from other entomogenous species of Sporothrix by its conidiogenous cells, which have scattered conidium-bearing denticles in the apical region; the conidiiferous rachis is not differentiated from the basal part. Furthermore the shape and size of the conidia are diagnostic. No secondary conidia were observed.

 

 

8. Sporothrix ramosissima Arnaud ex de Hoog, sp. nov. — Fig. 11

 

Gonatobotrys ramosissima Arnaud — Bull. trimest. Soc. mycol. Fr. 68: 187. 1952 (without Latin diagnosis).

 

Coloniae in vitro post 10 dies 23 mm diametro, floccosae, pulvinatae, hyalinae, deinde cremeae. Reversum citrinum. Hyphae hyalinae, in grege luteolae, rugulosae. Cellulae conidiogenae in parte apicali hypharum plus minusve dichotomico vel irregulariter ra­mosarum oriundae, cylindricae, singulae vel ramosae, longitudine variabiles, latitudine uniformes 1.5-2.5 pars apicalis suprema incremento sympodiali conidia formans, ex fasciculo denticulorum inflato consistens; denticuli obtusi. Conidia hyalina, asperula, obovata, (3.5-)5.5-6.5(-8) x 2.8-4.3 µm. Status perfectus ignotus.

Typus sub numero 3011 in herbario G. Arnaud (PC), in ligno humido lacus herbas continentis, Cavillargues, Gallia.

 

Colonies in vitro attaining a diameter of 23 mm in 10 days, appearing floccose, pulvinate, white, later becoming slightly cream coloured. Reverse [p. 29] citron yellow. Exudate and odour absent. Submerged hyphae hyaline, yellowish in mass, slightly rough-walled, about 2-3.5µm wide. Aerial hyphae somewhat rough-walled, usually about 2-4 µm wide, loose. Conidiogenous cells arising in the apical region of more or less dichotomously or irregularly branched hyphae, often integrated in short side branches, simple, or dichotomously or irregularly branched in first, second or third order, of variable length; apical branches usually shorter than the basal ones, cylindrical, width uniform 1.5-2.5 µm throughout; ultimate apical part forming conidia by sympodial growth, consisting of a swollen (up to 4 µm) cluster of conidium-bearing denticles; denticles flat, blunt, usually less than 0.5µm long, often very broad and scar-like. The conidiogenous cell often proliferates at or somewhat below the apex, which leads to a long, nodose conidiiferous rachis. Conidia hyaline, finely echinulate, obovate, with a wide scar at the base, (3.5-)5.5-6.5(-8) x 2.8-4.3µm. Perfect state unknown.

 

 

Fig. 11. Sporothrix ramosissima, CBS 326.72. a. conidial apparatus; b. branching system; c. conidia.

 

Material examined

 

Herbarium specimen

Type of Gonatobotrys ramosissima in herb. PC, Arnaud 3011, on moist wood of vegetable box, Cavillargues, France, June 1951. [p. 30]

 

Living strain

 

CBS 326.72 isolated by J. Chabert from air under no. 5111, Rabat, Marocco, preserved in coll. PC as Sporotrichum sp.

 

Discussion

 

Sporothrix ramosissima is distinct from all other species described in the genus owing to the occurrence of strikingly branched conidiogenous cells. Large conidiogenous cells are often slightly pigmented at the base. After formation of some conidia the cells frequently become septate; thus a conidiophore with intercalary conidiogenous cells is formed. If on the contrary lateral conidiogenous cells remain relatively short, basal septa are often not formed. Similar siting of septa is also observed in Sporothrix species with cylindrical conidiogenous cells, viz. S. fungorum, S. cyanescens and S. foliorum.

The ultimate branches of conidiogenous cells often proliferate, leading to a nodose conidiiferous rachis composed of a series of intercalary clusters of denticles. The denticles are blunt, similar to those of S. foliorum. The conidia have a rather wide scar at the base; this is also found in S. ghanensis and in the conidial state of Ophiostoma epigloeum.

Sporothrix ramosissima resembles some Nodulisporium species, e.g. N. album Preuss. Because of the similarities with other Sporothrix species, as mentioned above, it is thought here preferable to describe the present species in the genus Sporothrix.

 

 

Fig. 12. Sporothrix foliorum, CBS 326.37. a. conidial apparatus; b. conidia.

 

 

9. Sporothrix foliorum J. J. Taylor — Fig. 12

 

Sporothrix foliorum J. J. Taylor — Mycologia 62: 809. 1970.

Colonies in vitro attaining a diameter of 1 mm in 10 days, appearing somewhat farinose, flat or finally with a convex, lobed and folded [p. 31] ground-mycelium, in that case up to 3 mm high, white, later becoming pale yellowish grey. Reverse yellowish. Exudate and odour absent. Submerged hyphae hyaline, smooth- and thin-walled, often also slightly rough- and thick-walled hyphae present, 1.2-2.5(-3) µm wide, often with terminal and intercalary swellings, loose or compact. Aerial hyphae, if present, hyaline, smooth-walled, somewhat stiff, occasionally in a more or less hymeniform layer. Conidiogenous cells often slightly rough-walled, arising plagiotropically in the apical region of ascending or suberect hyphae, straight, cylindrical, occasionally slightly tapering towards the tip, often without basal septum, (4-)10-20(-32) x 1.3-2 µm; apical part forming conidia by sympodial growth, consisting of a swollen (up to 3 µm) cluster of conidium-bearing denticles; denticles very short, usually scar-like, less than 0.5 µm long. Sometimes the conidiogenous cell proliferates at the apex and gives rise to another cluster of denticles or a conidiogenous cell, which rarely in turn becomes intercalary. Conidia hyaline, smooth- and thin-walled, obovate to ellipsoidal, with a hilum at the base, 2.8-3.5(-4.3) x (1.6-)2-2.6(-2.9) µm. Perfect state unknown.

 

Material examined

 

CBS 326.37, type culture, isolated by Unilever.

 

Discussion

 

Sporothrix foliorum can be recognized by its rather short cylindrical conidiogenous cells and its small ellipsoidal conidia. Secondary conidia are only occasionally formed. The colonies of the species are striking owing to their limited growth on all agar media tested.

Conidiogenous cells are usually formed in the apical parts of the hyphae, which may be slightly differentiated. However, the fertile hyphae slowly merge into the vegetative mycelium and no conspicuous, erect conidiophores, as in Calcarisporium, are formed.

The flat, scar-like conidium-bearing denticles, and the occurrence of slightly rough-walled hyphae are reminiscent of Nodulisporium. However, Nodulisporium species with short cylindrical conidiogenous cells are usually characterized by spreading, lanose cultures, pigmented, conspicuously warty hyphae, a more or less verticillate branching pattern, and the septa delimiting the conidia are remote, leaving at liberation a distinct collar at both the conidiogenous cell and at the conidial base. For these reasons the genus Sporothrix is thought to be more appropriate for this species.

The only known strain, CBS 326.37, was formerly identified by F. H. van Beyma as Sporotrichum foliorum Desm. After study of the type material of the latter species, Taylor (1970c) considered it as a nomen dubium, and described CBS 326.37 as a new species. [p. 32]

 

 

10. Sporothrix setiphila (Deighton & Pirozynski) de Hoog, comb. nov.

 

Calcarisporium setiphilum Deighton & Pirozynski — Mycol. Pap. 128: 100. 1972 (basionym).

 

Discussion

 

This species, which was fully described and depicted by Deighton & Pirozynski (1972), is characterized by thin, undifferentiated hyphae, from which the conidiogenous cells mostly arise orthotropically. This type of arrangement of conidiogenous cells is characteristic for many species of Sporothrix, e.g. S. schenckii, whereas Calcarisporium is defined here as having erect conidiophores, provided with whorls of plagiotropic conidiogenous cells. Consequently the present species is better referred to as Sporothrix setiphila.

In the type material (CMI), which is the only collection of the species, the fungus overgrew Meliola clerodendri Hansf. on a leaf of Clerodendrum sp. in Tanzania. No living cultures were available. It differs from other species described in Sporothrix, apart of its parasitic character, by the fragile aerial mycelium, the shape and size of the conidia and by the slightly swollen clusters of small, blunt denticles. No secondary or lateral blastoconidia were observed.

 

 

Fig. 13. Sporothrix curviconia. CBS 959.73. a. conidial apparatus; b. sympodial conidia; c. insertion of lateral conidia; d. detached lateral conidia. [p. 33]

 

 

11. Sporothrix curviconia de Hoog, sp. nov. — Fig. 13

 

Coloniae in vitro post 10 dies 10 mm diametro, farinosae, deinde plus minusve velutinae, paulo zonatae, niveae. Reversum pallide luteolum. Hyphae hyalinae, glabrae, tenuiter tunicatae. Cellulae conidiogenae in hyphis non differentiatis laxe oriundae, saepe intercalares, aciculares, (6-)20-35(-60) x1.2-2 µm; pars apicalis incremento sympodiali conidia formans, ex fasciculo denticulorum non vel plus minusve inflato consistens; denticuli pustuliformes. Conidia hyalina, glabra, guttuliformia ad fusiformia, curvata, 3.5-5.5(-7.1) x 1.5-2(-2.4) µm. Blastoconidia lateralia hyalina, glabra, tenuiter tunicata, guttuliformia. Status perfectus ignotus.

Typus CBS 959.73,sub numero 239-i ab J. Devois missus, ex Terminalia ivorensis isolatus, Silva Kouin, Ivory Coast.

 

Colonies in vitro attaining a diameter of 10 mm in 10 days, appearing farinose, later more or less velvety, somewhat zonate, white. Reverse very pale yellowish. Exudate and odour absent. Submerged hyphae regular, hyaline, smooth- and thin-walled, mostly about 1.5-3 µm wide, loose. Aerial hyphae mostly about 1-1.5 µm wide, branched irregularly, or somewhat verticillately in the lower parts. Conidiogenous cells usually scattered, arising terminally or laterally from undifferentiated hyphae or from short side branches, straight or curved, linear, widest near the base, slightly tapering towards the tip, (6-)20-35(-60) x 1.2-2 µm, in the submerged mycelium somewhat wider, average 2-3 µm; apical part forming conidia by sympodial growth, consisting of a not or slightly swollen (in the submerged mycelium often inflated, up to 5 µm) cluster of conidium-bearing denticles; denticles short, often blotch-like, 0.3-1 µm long. The conidiogenous cell, especially in the submerged mycelium, often proliferates at or somewhat below the apex and gives rise to another cluster of denticles or a conidiogenous cell, usually with an inflated conidiiferous part, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, guttuliform to fusiform, mostly flattened at one side or curved, with a rather blunt base, 3.5-5.5(-7.1) x 1.5-2(-2.4) µm. Lateral blastoconidia only little differentiated from the sympodial blastoconidia, hyaline, smooth- and thin-walled, usually guttuliform, 2.5-3.5 x 1.7-2.5 µm. Perfect state unknown.

 

Material examined

 

CBS 959.73, type culture, received from J. Devois, Paris, under no. 239-i,isolated from Terminalia ivorensis A. Chev., Forêt de Kouin, Ivory Coast.

 

Discussion

 

The species can easily be recognized by its abundant unequilateral conidia, which have a narrow base. In other species of Sporothrix with curved conidia, such as S. luteoalba and the conidial state of Ophiostoma microsporum, the conidia are reniform, not tapering towards the base, and [p. 34] the conidiogenous cells are wider and shorter, much more irregular in shape.

Sporothrix curviconia is closely related to S. schenckii, but is distinct, apart from the differences in both sympodial and lateral conidia, by its colony aspects, and the inflated conidiiferous parts of the conidiogenous cells in the lower part of the mycelium. Sporothrix inflata is also similar, but differs i.a. by the brown lateral conidia.

 

 

Fig. 14. Sporothrix inflata, from living cultures. a. terminal and lateral conidiogenous cells; b. sympodial conidia; c. lateral conidia; d. intercalary conidiogenous cells.

 

 

12. Sporothrix inflata de Hoog, sp. nov. — Fig. 14

 

Gonatobotrys sp., Gams & Domsch — Nova Hedwigia 18: 12. 1969.

Sporothrix sp., von Klopotek — Arch. Mikrobiol. 85: 132. 1972.

 

Misapplied name

Sporothrix schenckii Hektoen & Perkins sensu Staib & al. — Zentbl. Bakt. ParasitKde, Abt. 1, 221: 95. 1972.

 

Coloniae in vitro post 10 dies 8-18 mm, floccosae vel funiculosae, interdum leves, primum griseae ad olivaceae, mox nigrescentes. Reversum nigrum. Hyphae hyalinae ad pallide olivaceae, glabrae vel rugulosae. Cellulae conidiogenae in hyphis non differentiatis laxe oriundae, saepe intercalares, lineares vel aciculares, 30-50 x 1-2 µm; pars apicalis incremento sympodiali conidia formans, ex capitulo denticulorum globoso con­sistens; denticuli pustuliformes ad subcylindracei. Conidia hyalina, glabra, guttuliformia ad fusiformia, (3-)4-6(-8.7) x 2-2.5(-3) µm. Blastoconidia lateralia numerosa, globosa, 3-4 µm diametro, crassiuscule tunicata, brunnea. Status perfectus ignotus.

Typus CBS 239.68, ex terra agri triticei, Germania occidentalis, ab W. Gams isolatus. [p. 35]

 

Colonies in vitro attaining a diameter of 8-18 mm in 10 days, appearing floccose, lanose or somewhat funiculose, often partially or completely remaining smooth, at first grey to olivaceous, soon becoming blackish. Reverse grey olivaceous, often somewhat zonate, finally becoming black due to abundant formation of lateral blastoconidia. Exudate and odour absent. Hyphae hyaline or pale olive, smooth- or slightly rough-walled, thin-walled, 1-2.5 µm wide, loose or fasciculate. Conidiogenous cells scattered, arising orthotropically from undifferentiated hyphae, often also in terminal position or integrated in short side branches, straight or curved, linear, widest near the base, slightly tapering towards the tip, continuous, sometimes septate, average 30-50 µm long and 1-2 µm wide; apical part forming conidia by sympodial growth, consisting of a globose, swollen (diameter usually 3-4.5 µm) cluster of conidium-bearing denticles; denticles blotch-like to subcylindrical, 0.5-1(-1.5) µm long. The conidiogenous cell often proliferates at or somewhat below the apex and gives rise to another conidiogenous cell, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, guttuliform to fusiform, with a pointed base, (3-)4-6(-8.7) x 2-2.5(-3) µm. Rarely some secondary conidia are formed. Lateral blastoconidia abundant, globose (diameter usually 3-4 µm), some-what thick-walled, brown. Perfect state unknown.

 

Material examined

 

Herbarium specimen

 

IMI 149.504, dried culture, isolated by G. C. Bhatt from corn-field soil, Bright, Ontario, Canada, July 1967.

 

Living strains

 

CBS 239.68, type culture, isolated by W. Gams from wheat-field soil, W-Germany, as Gonatobotrys sp., and numerous other strains from soil in Europe.

CBS 792.73, 840.73, 841.73 and numerous other strains isolated from soil near Valdivia, Chili, by J. Grinbergs.

CBS 793.73 isolated by A. von Klopotek from pasture soil, Solligen, W-Germany, sent as Sporothrix sp. under no. S-38.

CBS 794.73 isolated by B. Söderström from spruce forest soil, Skåne, Sweden, and several strains isolated from soil at Winterswijk, Netherlands.

 

Discussion

 

The present species is very similar to Sporothrix schenckii, but can be distinguished by the regular conidiogenous cells, on which the formation of conidia is restricted to a well differentiated globose head with denticles. Next to the head, some scattered conidia may be formed along the hyphae or conidiogenous cells; brown lateral blastoconidia are always abundant. Proliferation of conidiogenous cells is very common, and leads to nodose hyphae with intercalary swollen clusters of denticles. [p. 36]

Sporothrix inflata is a common species, occurring in different types of soil. 44 Strains were mentioned by Gams & Domsch (1969); 18 strains were sent by Prof. J. Grinbergs, and 6 by B. Söderström. CBS 793.73, kindly sent by Mrs A. von Klopotek, formed in fresh cultures a small number of allantoid conidia; after some transfers, however, this conidial type was lost, and the strain was indistinguishable from S. inflata. The same strain was mentioned by Staib & al. (1972) as Sporothrix schenckii.

In shake culture the yeast-like form is not stimulated, as in S. schenckii. In such cultures the conidiogenous cells, if present, are very irregular, usually rather short and wide, with blunt denticles in the apical region; the swollen heads are less pronounced. The conidia are obovate, and sometimes resemble the lateral blastoconidia, which are pale brown under these circumstances.

 

 

Fig. 15. Sporothrix schenckii sensu lato, from living cultures. a. terminal and lateral conidiogenous cells; b. proliferating conidiogenous cells; c. sympodial conidia; d. lateral conidia.

 

 

13. Ophiostoma stenoceras (Robak) Melin & Nannf. — Fig. 15

 

Ceratostomella stenoceras Robak — Nyt Mag. Naturvid. 71: 207. 1932 = Ophiostoma stenoceras (Robak) Melin & Nannf. Svenska SkogsvFör. Tidskr. 32:408. 1932 = [p. 37] Ceratocystis stenoceras (Robak) C. Moreau — Revue Mycol., Suppl. Colon. 17: 22. 1952.

Ophiostoma albidum Mathiessen-Käärik — Meddr. St. SkogsvFör. Inst. 43: 50. 1953 = Ceratocystis albida (Mathiessen-Käärik) Hunt — Lloydia 19: 48. 1956.

 

States conidialis (pro parte): Sporothrix schenckii Hektoen & Perkins — Fig. 15

 

Sporotrichum sp., E. F. Smith in Schenck — Johns Hopkins Hosp. Bull. 93: 288. 1898.

Sporothrix schenckii Hektoen & Perkins — J. exp. Med. 5:77. 1900 = Sporotrichum schenckii (Hektoen & Perkins) de Beurmann & Gougerot — Archs Parasit. 15:5. 1911 = Sporotrichum schenckii-beurmannii Greco var. schenckii (Hektoen & Perkins) de Beur­mann & Gougerot — Archs Parasit. 15: 38. 1911 = Rhinocladium schenckii (Hektoen & Perkins) Verdun — Précis Parasitol., éd. 2. 1913 = Rhinotrichum schenckii (Hektoen & Perkins) Ota — Jap. J. Dermatol. Urol. 27: 921. 1927 = Sporotrichum beurmannii Matr. & Ramond var. schenckii (Hektoen & Perkins) Red. & Cif. — Tratt. Micopat. umana 5: 452. 1942.

Sporotrichum beurmannii Matr. & Ramond — C. r. hebd. Séanc. Mém. Soc. Biol. 2: 380. 1905 = Trichosporium beurmannii (Matr. & Ramond) Lutz & Splendore — Annali Ig. sper. 17: 581. 1907 = Rhinocladium beurmannii (Matr. & Ramond) Vuill. — Bull. Séanc. Soc. Sci. Nancy 11: 138. 1910 = Sporotrichum schenckii-beurmannii Greco var. beurmannii (Matr. & Ramond) de Beurmann & Gougerot — Archs Parasit. 15: 39. 1911 = Sporotrichopsis (?) beurmannii (Matr. & Ramond) Gueguen in de Beurmann & Gougerot — Archs Parasit. 15: 104. 1911 = Sporothrix beurmannii (Matr. & Ramond) Meyer & Aird — J. infect. Dis. 16: 399. 1915 = Rhinotrichum beurmannii (Matr. & Ramond) Ota — J. Jap. Dermatol. Urol. 28: 4. 1928 = Sporotrichum schenckii (Hektoen & Perkins) de Beurmann & Gougerot var. beurmannii (Matr. & Ramond) C. W. Dodge — Med. Mycol. p. 805. 1935.

Sporotrichum schenckii-beurmannii Greco — Argent. Med. 45: 699. 1907 (nomen nudum) = Sporothrix schenckii-beurmannii (Greco) Meyer & Aird — J. infect. Dis. 16: 407. 1915 (incidentally mentioned).

Sporotrichum asteroides Splendore — Revta Soc. scient. S. Paulo 3: 62. 1908 = Sporotrichum beurmannii Matr. & Ramond var. asteroides (Splendore) de Beurmann & Gougerot — Rev. med. Trop. Hyg. 7: 185. 1910 = Rhinocladium asteroides (Splendore) Verdun — Precis Parasitol., éd. 2. 1913 = Sporothrix asteroides (Splendore) J. Davis — J. infect. Dis. 12: 453. 1913 = Rhinocladium beurmannii (Matr. & Ramond) Vuill. var. asteroides (Splendore) C. W. Dodge (as ‘Vuill’.) — Med. Mycol. p. 802. 1935 = Rhinotrichum asteroides (Splendore) C. W. Dodge (as ‘Verdun’) — Med. Mycol. p. 802. 1935.

Sporotrichum indicum Castell. — J. trop. Med. Hyg. 11: 261. 1908 (without diagnosis) = Sporotrichum beurmannii Matr. & Ramond var. indicum (Castell.) de Beurmann & Gougerot — Les Sporotrichoses p. 179. 1912 (nomen provisorium) Rhinocladium indicum (Castell.) Verdun — Precis Parasitol., éd. 2. 1913 = Rhinotrichum indicum (Castell.) Ota — Jap. J. Dermatol. Urol. 27: 928. 1927.

Sporotrichum equi Carougeau — J. med. vét. Zootechn. 60: 80. 1909 = Rhinocladium equi (Carougeau) Lurie — Mycologia 40: 107. 1948 (as ‘equinum’).

Sporotrichum sp., Jeanselme & Chevallier — Bull. Mém. Soc. med. Hop., Paris 29:792. 1910 = Sporotrichum jeanselmei Brumpt & Langer. — Précis Parasitol., éd. 1. 1910 (non Torula jeanselmei Langer. — Annls Parasit. hum. comp. 6: 385. 1928) = Sporo­trichum beurmannii Matr. & Ramond var. jeanselmei (Brumpt & Langer.) de Beurmann & Gougerot — Archs Parasit. 15: 51. 1911 = Rhinocladium jeanselmei (Brumpt & Langer.) Verdun — Précis Parasitol., éd. 2. 1913 = Rhinotrichum jeanselmei (Brumpt & Langer.) Ota — Jap. J. Dermatol. Urol. 28: 5. 1928.

Sporotrichum fonsecae Filho — Revta med.-cirurg. Braz. 37: 265. 1929 = Rhinocladium fonsecae (Filho) Filho — Revta med.-cirurg. Braz. 38: 163. 1930.

? Sporotrichum grigsbyi C. W. Dodge — Med. Mycol. p. 801. 1935 (without Latin diagnosis).[p. 38]

Rhinocladium sp., MacKinnon — Archos Soc. biol. Montev. 5: 1325. 1931 = Sporo­trichum schenckii (Hektoen & Perkins) de Beurmann & Gougerot var. greconis C. W. Dodge — Med. Mycol. p. 808. 1935 (without Latin diagnosis) = Sporotrichum greconis Gougerot — Ann. N. Y. Acad. Sci. 50: 1348. 1950 (incidentally mentioned).

Sporotrichum (Rhinocladium) verticilloides A. Sartory & al. — C. r. hebd. Séanc. Acad. Sci., Paris 201: 1501. 1935.

Rhinocladium pereirae Miranda — Um novo Esporotricado. 1936 (without Latin diag­nosis) — Sporotrichum pereirae (Miranda) Red. & Cif. — Tratt. Micopat. umana 5: 460. 1942.

Sporotrichum (Rhinocladium) tropicale Panja & al. — Indian med. Gaz. 82: 202.1947 (without Latin diagnosis).

Sporotrichum acuminatum Lurie — Mycologia 43: 120. 1951 (without diagnosis). Calcarisporium pallidum Tubaki — Nagaoa 5: 13. 1955.

Sporothrix albicans S. B. Saksena — Curr. Sci. 34: 318. 1965.

 

Misapplied name

 

Gonatobotrys microspora Rivolta sensu Swart — S. Afr. J. Sci. 55: 49. 1959.

 

Colonies in vitro attaining a diameter of 6-22 mm in 10 days, of very variable appearance: at first usually smooth, soon becoming finely floccose, velvety, lanose or somewhat funiculose; if remaining smooth by absence of aerial hyphae, the colony is flat or furrowed brain-like and rather compact. Moderately rapidly growing cultures (usually conidial states of Ophiostoma stenoceras) are lanose from the beginning. Colonies at first hyaline, later often becoming greyish to dull brown; lanose colonies white, freshly isolated cultures may occasionally be blackish. Reverse uncoloured or yellowish, often becoming grey, grey brown or black by abundant formation of lateral blastoconidia. Hyaline exudate rarely produced; odour absent. Submerged hyphae hyaline, occasionally pale brown, smooth-walled, thin- or sometimes slightly thick-walled, (0.7-)1-2(-3) µm wide. Aerial hyphae, if present, thinner than the submerged hyphae, loose or somewhat fasciculate. Conidiogenous cells scattered, arising orthotropically from undifferentiated hyphae, often also in terminal position or integrated in short side branches, continuous, linear, variable in shape and size, widest near the base and slightly tapering towards the tip, mostly about 10-40 µm long and as wide as the supporting hypha, 0.7-1.5(-2) µm; apical part forming conidia by sympodial growth, consisting of a not or slightly swollen (in conidial states of O. stenoceras rarely up to 3.5 µm) cluster of conidium-bearing denticles; denticles blotch-like to subcylindrical, usually 0.5-1 µm long. The conidiogenous cell often proliferates at or somewhat below the apex and gives rise to another cluster of denticles or a conidiogenous cell, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, guttuliform to fusiform, with a pointed base, 2.5-5.5(-8) x 1.5-2.5(-3) µm. Rarely some secondary conidia are formed. When older brown or hyaline, somewhat thick-walled, subglobose or slightly triangular lateral blastoconidia (about 3 µm in diameter) may be present. [p. 39]

 

Material examined

 

Herbarium specimens

 

IMI 99642, dried culture on PDA, isolated by B. A. Indraratne from needles of Pinus nigra, Freshfield, Great Britain, May, 1972 as Sporothrix sp.

IMI 163880, dried culture, isolated by D. Hunt from contaminated tanning liquors (Acacia mollisima), Great Britain, February, 1972, as Sporothrix sp.

 

Living strains

 

Representative strains with perithecia:

CBS 139.50 (= ATCC 8713) sent by R. W. Davidson in 1942 under no. USDA 608-E as Ceratostomella pilifera.

CBS 104.66 sent by Unilever, identified by J. A. von Arx as Ceratocystis pilifera.

CBS 360.71(= IP 1013-70) isolated from haired skin of man, France, sent by F. Mariat under no. G-118, identified by R. W. Davidson and J. J. Taylor, and CBS 361.71 (= IP 1021-70), conidial mutant of CBS 360.71, sent by F. Mariat under no. G-1518 A-II.

 

Strains with imperfect state only:

CBS 356.29 (= ATCC 14096) sent by M. Engelhardt, Giessen, as Sporotrichum asteroides.

CBS 237.32, type culture of Ceratostomella stenoceras, isolated by H. Robak from wood pulp, Norway.

CBS 253.33 sent by E. Melin as Ceratostomella stenoceras.

CBS 340.35 isolated by Y. Kobayashi from man, Japan, sent by M. Ota under no. 510 as Sporotrichum beurmannii.

CBS 359.36, possible type culture of Sporothrix schenckii, sent by D. J. Davis under no. 431.

CBS 327.37 isolated from human eye abscess, Italy, sent by O. Verona as Sporotrichum beurmannii.

CBS 472.48 isolated by M. Langeron, sent by N. F. Conant.

CBS 201.53 isolated from rotten grass, South Africa, sent by H. J. Swart under no. 130, identified by M. B. Schol-Schwarz as Gonatobotrys microspora.

CBS 345.53 isolated from man, Amsterdam, sent by W. Graafland.

CBS 292.55, type culture of Sporotrichum tropicale, isolated from man, sent in 1947 by L. M. Ghosh under no. S-480.

CBS 131.56, type culture of Calcarisporium pallidum, isolated by K. Tubaki from Stemonites fusca Roth, Mt. Oomine, Gumma Prefecture, Japan, July 1954.

CBS 136.56 (= ATCC 8714 = USDA 731) sent by R. W. Davidson as Ophiostoma pluriannulatum.

CBS 211.61 (=IMB 635) isolated by H. I. Lurie, South Africa, under no. 8, sent by G. Müller  as Sporotrichum asteroides.

CBS 182.63 isolated from soil by J. H. van Emden, Netherlands, October 1963, sent by L. Hennebert as Calcarisporium pallidum.

CBS 444.67 isolated from man, Mozambique, sent by G. Magalhaês under no. 1380.

CBS 937.72 (= ATCC 18616), type culture of Sporothrix schenckii var. luriei, isolated by H.I. Lurie from man, South Africa, sent by L. Ajello under no. B-1040.

CBS 938.72 isolated from man, sent by F. Mariat under no. IP 29, described by Ansel Sc. Thibaut (1970) as Dolichoascus schenckii.

CBS 302.73 (= IMI 80,677), type culture of Sporothrix albicans, isolated by S. B. Saksena from soil, Cambridge, England, 1964.

CBS 798.73 sent by A. Mathiesen-Käärik as Ceratocystis albida. [p. 40]

 

Discussion

 

Descriptions of the perfect state of Ophiostoma stenoceras were given by Robak (1932, as Ceratostomella stenoceras), Davidson [1942, as ?Ceratostomella (Ophiostoma) stenoceras], Mathiesen-Käärik (1953, as Ophiostoma albidum) and Mariat (1971a, as Ceratocystis stenoceras).

The type culture of Ceratostomella stenoceras, CBS 237.32, has lost the ability to produce perithecia. This has already been reported by Hunt (1956),who listed it as a doubtful species.Griffin (1968) reintroduced the name for a species with small ascospores and long ostiolar hyphae. Unfortunately his material was not available for study. Mariat (1971a) used the name Ceratocystis stenoceras for a fungus of which the conidial state differs only very slightly from the original material of Robak; as in this strain (CBS 360.71) both perfect and imperfect states are well developed, the above description is based on it.

Ophiostoma albidum was mentioned by Griffin (1968) as a close relative of Ophiostoma stenoceras. A culture of the species was kindly sent by Dr A. Mathiesen-Käärik. Its conidial state appeared to be indistinguishable from CBS 360.71; no perithecia were observed in the present strain. According to the original description the perfect state should differ from O. stenoceras mainly by the smaller basal parts of the perithecia (66-85 µmin pure culture, 110-164 µmon wood). In view of the considerable variability of perithecial dimensions, O. albidum is treated here as a synonym of O. stenoceras.

Ophiostoma stenoceras is a common saprophyte on wood (Davidson, 1942; Mathiesen-Käärik, 1953; Griffin, 1968) and other substrata. It is closely related to some blue staining fungi, e.g., O. piliferum and O. piceae, from which it differs mainly by the characteristics of the conidial states. Numerous very similar species have been described, some of which might be indentical; however, no type material of these species was available for study.

The similarity of the conidial state of Ophiostoma stenoceras with Sporothrix schenckii was discussed by Mariat & al. (1968), Mariat (1971a and b) and Andrieu &, al. (1971); the resemblance between S. schenckii and some other Ophiostoma species was discussed by Taylor (1970b). During the present study it indeed appeared to be impossible to find steady morphological differences between S. schenckii and the conidial states of O. stenoceras and O. tetropii. Ophiostoma narcissi is also similar, but can be distinguished by its choice of substratum. For this reason S. schenckii is described here jointly with both Ophiostoma conidial states. It must be stated, however, that the range of variability in the conidial states of Ophiostoma stenoceras and O. tetropii does not exactly correspond with that of Sporothrix schenckii: usually the Ophiostoma colonies are more extended, floccose, the conidiogenous cells are somewhat wider and more regular, the conidia may be longer, fusiform, and finally the lateral conidia are often almost hyaline.

Sporothrix schenckii is a facultative but highly virulent parasite on man [p. 41] (Hektoen & Perkins, 1900; Simons 1954; Findley, 1970), occasionally occurring on animals. The species has also been isolated from timber (Brown & al., 1947), grass and soil (MacKinnon & al., 1969) and other substrates. A vast number of studies in vivo has been published since its discovery in 1898.

In culture, even under standard conditions, the species is very variable. Usually it can be recognized by the conidiogenous cells which arise more or less orthotropically from thin, undifferentiated hyphae, the small, unswollen cluster of conidium-bearing denticles, and the absence or local occurrence of secondary conidia, which never arise in chains. Its affinities are with Sporothrix curviconia and S. inflata, which differ by the presence of curved conidia and of well differentiated heads of conidium-bearing denticles, respectively.

In most cultures of Sporothrix schenckii two types of conidia occur. In young cultures the conidia are formed blastically by sympodial growth of the tip of the conidiogenous cell (‘conidia type I’, Mariat & al., 1962). In this case the conidiogenous locus coincides, at least in the beginning, with the growing tip of the conidiogenous cell, giving rise to a thin-walled, hyaline conidium. After some days often also lateral conidia arise on mature, intercalary hyphal cells (‘conidia type II’, Mariat & al., 1962).

 

 

Fig. 16. Sporothrix schenckii, CBS 359.36, hanging drop culture on 2% malt agar. a. normal conidiogenous cells; b. formation of secondary conidia; c. proliferating conidiogenous cells. [p. 42]

 

Usually conidia of this type become brown and somewhat thick-walled. They are known in the literature as chlamydospores (Dodge, 1935), pseudoblastospores (Mariat & al., 1962), macrospores (Nicot & Mariat, 1973) and aleuriospores (de Bertoldi & al., 1972). If strong proliferation near the tip of the conidiogenous cell occurs immediately after initiation of an apical conidium, blastic conidia can be formed on the edges of an irregularly geniculate conidiiferous rachis (Fig. 16c). They may be light brown and intermediate in shape and wall structure between the conidial types mentioned above. This intermediate type occurs especially in desiccating cultures and can clearly be observed near the margin of old hanging drop cultures.

Locally secondary and tertiary conidia may be formed by sprouting of hyaline primary conidia (Fig. 16b). Secondary conidia are subspherical and occur especially on detached, swollen primary conidia. The conversion into more or less yeast-like colonies is stimulated in shaken cultures at 37°C in liquid media as described by Mariat & de Bièvre (1968). A review of all conidial states of the present species was given by Nicot & Mariat (1973).

After examination of many living strains it was concluded that no different taxa could be distinguished within the Sporothrix schenckii complex. Hence, several still current names in the literature are regarded here as synonyms of S. schenckii. Most of them are discussed below in chronological order.

Sporothrix schenckii. The clinical features of the fungus were first described by Schenck (1898), who mentioned it as Sporotrichum sp. A second case was reported by Hektoen & Perkins (1900); the fungus was clearly described and depicted as Sporothrix schenckii. Subcultures of the type strain were obtained by de Beurmann & Gougerot (1912) as ‘Hektoen-initial’, and by Davis (1913) as ‘strain C’. No material was available in PC. In 1936 Davis sent a strain of S. schenckii to the CBS under no. 431, without further information. The strain fits the description made by Hektoen & Perkins (1900) in all respects, and is probably a subculture of the type strain.

Sporotrichum beurmannii was not available in PC. Its identity with S. schenckii was suggested by Davis (1920).

Sporotrichum schenckii-beurmannii was proposed by Greco (1907) to maintain the names of the American and French Sporotrichoses, which were both used frequently. No type material was deposited.

Sporotrichum asteroides is commonly regarded as a variety of S. schenckii. Possibly no type material is preserved. It was mainly separated on the basis of the properties of the asteroid bodies in formalin fixed tissues. However, Lurie & Still (1969) proved that these bodies are artefacts.

Sporotrichum indicum. According to Davis (1920) the type material is lost. It was published by Castellani (1908) without description. De Beurmann & Gougerot (1912) mentioned some very slight distinctive characters. Davis (1920) considered the species to be identical with S. schenckii. [p. 43].

Sporotrichum grigsbyi was originally mentioned by Grigsby & Moore (1922) as Sporothrix schenckii. No statements were made about its morphology. Based upon its biochemical behaviour Dodge (1935) regarded it as a new species, but he did not give a Latin diagnosis. As the colonies were said to be pinkish after 6 days on potato or plain agar, its identity with S. schenckii remains uncertain.

Sporotrichum (Rhinocladium) verticilloides. The identity of this species with S. schenckii was discussed by Müller (1966).

Rhinocladium pereirae. Müller (1965) mentioned the species as a synonym of S. schenckii. This was confirmed by the observations of von Arx (CBS-file of cultures) on the type strain, CBS 471.48. This strain was in bad condition and was maintained until 1968.

Gonatobotrys microspora. No type material of this species was available in PAD and PAV. According to Matruchot (1903) a Cunninghamella species was concerned; Swart (1959) and Samson (1969), however, thought it from the figures of Rivolta (1873) to be a Hyphomycete. The drawings given by Swart (1959) from his own isolate, CBS 201.63, are somewhat misleading: swollen sympodial heads of that size could not be observed in this strain by the present author.

Dolichoascus schenckii Thibaut & Ansel in Ansel & Thibaut was invalidly published (without indication of type material) in the Endomycetes as the perfect state of Sporothrix schenckii. According to Mariat & Diez (1971) strain IP-29 (= CBS 938.72) was concerned. The latter authors did not observe any sexual process in this strain, though an endoconidial state, very similar to Dolichoascus schenckii occurred abundantly. Consequently the results of Ansel & Thibaut (1970) were doubted.

 

All taxa described as varieties of Sporothrix schenckii, which are not identical with it, are briefly discussed below in alphabetical order.

 

a n g l i c u m. — Sporotrichum anglicum Castell. — J. trop. Med. Hyg. 40: 313. 1937 = Sporotrichum beurmannii Matr. & Ramond var. anglicum (Castell.) Red. & Cif. — Tratt. Micopat. umana 5: 459. 1942.

Feo (1963) studied one of the original strains and thought it to be identical with Trichosporon behrendii Lodder & van Rij, the conidial state of Pichia burtonii Boidin & al. Müller (1964) however identified it as Trichosporon variabile (Lindner) Delitsch.

 

c a r o u g e a u i. — Sporotrichum carougeaui Langer. — Bull. Soc. Path. exot. 15: 453..1922 = Rhinocladium carougeaui (Langer.) C. W. Dodge (as ‘Neveu-Lemaire) — Med. Mycol. p. 804. 1935 = Sporotrichum beurmannii Matr. & Ramond var. carougeaui (Langer.) Red. & Cif. — Tratt. Micopat. umana 5: 458. 1942.

According to Pijper (1931) the original material is lost. Müller (1964) examined a number of CBS strains which fitted the diagnosis. As a result he listed the species as a synonym of the conidial state of Pichia burtonii. This conclusion was confirmed by the Yeast Division of the CBS for all [p. 44] but one strain: CBS 5057 (= Müller 298) was identified as Trichosporon fermentans Diddens & Lodder.

 

castellanii. — Acladium castellanii Pinoy in Castell. — Brit. med. J. 2910: 486. 1916 = Pseudomicrosporon castellanii (Pinoy in Castell.) Craik — J. trop. Med. Hyg. 26: 186. 1916 = Aleurisma castellanii (Pinoy in Castell.) Vuill. — Champ. paras. Myc. homme p. 115. 1931 = Sporotrichum beurmannii Matr. & Ramond var. castellanii (Pinoy in Castell.) Red. & Cif. — Tratt. Micopat. umana 5: 481. 1942 = Sporotrichum schenckii (Hektoen & Perkins) de Beurmann & Gougerot var. castellanii (Pinoy in Castell.) Red. & Cif. (as ‘Butler’) — Tratt. Micopat. umana 5: 481. 1942.

One of the original strains isolated by Castellani was fully described and depicted by Butler (1937). In the type culture, CBS 100.26, sporulation now has decreased considerably, and no synnemata are produced any more. Truncate blastoconidia arise in groups of 1-3(-5) at the tips of subhyaline, cylindrical conidiogenous cells, which now occurred scattered along undifferentiated hyphae. The species resembles some poorly developed conidial states of Ophiostoma species, e.g. O. bicolor Davidson & Wells, and can be classified as Raffaela castellanii (Pinoy in Castell.) de Hoog, comb. nov. Morphologically there is also some similarity with Scedosporium apiospermum (Sacc.) Sacc. and other conidial states of Petriellidium species.

 

councilmannii. — Sporotrichum councilmannii Wolbach & al. — J. med. Res. 36: 337. 1917 = Rhinocladium councilmannii (Wolbach & al.) Neveu-Lemaire — Precis Parasitol., ed. 3. 1921 = Rhinotrichum councilmannii (Wolbach & al.) Ota — Jap. J. Dermatol. Urol. 28: 4. 1928 = Acremoniella councilmannii (Wolbach & al.) Vuill. — Champ. parasit. Myc. Homme p. 68. 1931 = Sporotrichum beurmannii Matr. & Ramond var. councilmannii (Wolbach & al.) Red. & Cif. — Tratt. Micopat. umana 5: 456. 1942.

Two strains were examined, viz. CBS 267.28 and CBS 357.29, sent by O. Gratz and M. Engelhardt, Giessen, respectively. The presumption of Müller (1964) that these strains are subcultures of the type strain, could not be ascertained. Both strains represent the conidial state of Petriellidium boydii (Shear) Malloch (type culture: CBS 101.22), described by Saccardo (1911) as Scedosporium apiospermum.

 

f i o c c o i. — Sporotrichum schenckii (Hektoen & Perkins) de Beurmann & Gougerot var. fioccoi C. W. Dodge — Med. Mycol. p. 808. 1935 The synonymy of this variety with Beauveria brongniartii (Sacc.) Petch was discussed by de Hoog (1972).

 

luriei. — Sporothrix schenckii Hektoen & Perkins var. luriei Ajello & Kaplan — Mykosen 12: 642. 1969.

This variety was described to accomodate a Sporothrix strain with a peculiar behaviour in vivo: it differs from S. schenckii by the production of sclerotia and by a considerable variation in shape of the yeast-like cells. [p. 45]

 

 

14. Ophiostoma tetropii Mathiesen

 

Ophiostoma tetropii Mathiesen — Svensk bot. Tidskr. 45: 228. 1951 = Ceratocystis tetropii (Mathiesen) Hunt — Lloydia 19: 45. 1956.

 

Discussion

 

The perfect state of this species can be recognized by its large perithecia with long necks which are swollen in the lower part and have a sharply differentiated fringe of erect ostiolar hyphae. The ostiolar hyphae are hyaline, thin-walled, erect or slightly curved inwards; the width is usually uniform throughout. The type strain CBS 140.51 still produced perithecia; some characteristics mentioned by Mathiesen (1951) and Mathiesen-Käärik (1960), as the yellow-brown appearance of the colonies and the brown perithecial hairs, were however lost. The colonies attained a diameter of 4 mm in 10 days (8.8 cm according to Mathiesen, 1951), remained white, and were microscopically indistinguishable from the conidial state of Ophiostoma stenoceras. The Sporothrix state as observed in the type strain possibly corresponds the ‘Cephalosporium-Typ’ as described and depicted by Mathiesen (1951). The same author also mentioned ‘Scopularia-ähnliche Konidienträger’. This state, which possibly is Verticicladiella Hughes, was not observed in the type strain.

 

 

15. Ophiostoma epigloeum (Guerrero) de Hoog, comb. nov. Fig. 17a-b

 

Ceratocystis epigloeum Guerrero — Mycologia 63: 921. 1971 (basionym).

 

Colonies in vitro attaining a diameter of 2 mm in 10 days, appearing finely floccose or velvety, up to 1 mm high, often locally lanose, higher and more extended; white. Reverse pale yellowish. Exudate and odour absent. Submerged hyphae hyaline, smooth-walled, very regular, 1.5-2 µm wide. Aerial hyphae thinner than the submerged hyphae, loose. Conidiogenous cells scattered, arising ortho- or slightly plagiotropically from undifferentiated hyphae, often also in terminal position or integrated in short side branches, continuous, often with an inconspicuous septum, linear, width rather uniform throughout 1.5-2 µm, basal part of the cell sometimes slightly swollen up to 2.5(-3) µm, usually about 15-30 µm long; apical part forming conidia by sympodial growth, consisting of an irregular, straight or geniculate rachis, provided with conidium-bearing denticles at irregular, usually large (2-20 µm) distances; denticles blotch-like, often inconspicuous, up to 0.5 µm long. The conidiogenous cell may proliferate at or somewhat below the apex and give rise to another conidiogenous cell. Conidia hyaline, smooth- and thin-walled, obovate, ellipsoidal or fusiform, with a rather wide, often slightly flattened point of attachment, 3.5-6.5(-8.2) x 2-3 µm. Rarely some secondary conidia are formed. [p. 46].

 

 

Fig. 17. a-b. Ophiostoma epigloeum, CBS 573.63. a. conidial apparatus; b. conidia. c-d. Sporothrix sp., CBS 129.32. C. conidiogenous cells; d. conidia.

 

Material examined

 

CBS 573.63 (= BAFC 2128), type culture of Ceratocystis epigloeum, isolated by R. T. Guerrero from Tremella fuciformis Berk., Tucuman, Argentina, sent by J. E. Wright, August 1963.

 

Discussion

 

In the type strain no perithecia could be observed. According to the description given by Guerrero (1971), O. epigloeum is very similar to Ophiostoma stenoceras and O. piceae. The same author also mentioned a collection of Sphaeronaema epigloeum Berk. & Br. amongst his examined materials of Ceratocystis epigloeum. However, the study of two specimens in the herbarium M. J. Berkeley (K), among which the type, revealed evidence that this species is distinct e.g. by small perithecia, the wall of which is composed of jig-saw-like cells, and broad, brown necks. No ascospores could be found in either specimens. [p. 47]

When O. epigloeum was cultivated in the dark growth was restricted, and abundant sporulation of the Sporothrix state was obtained. In daylight, especially when grown on malt agar, the cultures were more extended, attaining a diameter of 10-15 mm in 10 days, but often remained sterile. The conidial state can easily be recognized by the long rachids of the conidiogenous cells, which bear small, blotch-like denticles at large intervals. Occasionally, if the denticles are inconspicuous, it resembles the conidial state of Ceratocystis alba DeVay & al., which is distinct by conidia with truncate conidial bases.

There is still some doubt about the identity of CBS 126.39, 146.71 and 156.72. CBS 126.39 was sent by K. Zobl as Ophiostoma piceae, and was said to have a Graphium conidial state, which is lost now. It still produces perithecia in pure culture, which are indistinguishable from Ophiostoma stenoceras. CBS 146.71 was isolated from Erica gracilis in a glass house in W-Germany, and was identified by W. Gams as Ceratocystis stenoceras; though its perithecia are large, the strain fits in with the range of variability of this species. CBS 156.72 was isolated from glass-house soil in the Netherlands by Mrs H. Kaastra-Höweler, and was maintained in the CBS-collection as Sporothrix sp. No production of perithecia or Graphium-like synnemata was observed. The colonies of this strain are lanose, purely hyaline, though some subcultures had a slightly pinkish reverse; sometimes lateral blastoconidia were present. All strains mentioned above resemble the conidial state of Ophiostoma epigloeum in the very strong proliferation of the apical parts of the conidiogenous cells, leading to irregularly denticulate, nodose or more or less antler-shaped conidiiferous rachids (Fig. 17c). There are however some slight differences: the hyphae are narrower, the conidiogenous cells often longer, the conidia are narrower, fusiform, and have a more pointed, rarely flattened point of attachment. Consequently there is also some similarity with the proliferating conidiogenous cells as can be observed in hanging drop cultures of Sporothrix schenckii (Fig. 16), and the identity of the present strains can not be established.

 

 

16. Ophiostoma piliferum (Fr.) H. & P. Syd. — Fig. 18

 

Sphaeria pilifera Fr. — Syst. mycol. 2, p. 472. 1822 = Ceratostoma piliferum (Fr.) Fuckel — Symb. mycol. p. 128. 1869 = Ceratostomella pilifera (Fr.) Winter in Rabenhorst — KryptFl. 1, Pilze II, p. 252. 1887 = Linostoma piliferum (Fr.) Höhnel — Annls mycol. 16: 91. 1918 = Ophiostoma piliferum (Fr.) H. & P. Syd. = Annls mycol. 17: 43. 1919 = Ceratocystis pilifera (Fr.) C. Moreau — Revue Mycol., Suppl. Colon. 17: 22. 1952.

Ceratostomella coerulea Münch — Naturw. Z. Forst- u. Landw. 5: 561. 1907 = Ophiostoma coerulea (Münch) H. & P. Syd. — Annls Mycol. 17: 43. 1919 = Ceratocystis coerulea (Münch) C. Moreau — Revue Mycol., Suppl. Colon. 17: 22. 1952.

 

Colonies in vitro attaining a diameter of 38-47 mm in 10 days, appearing flocculose, aerial tufts of mycelium often adhered to the agar, less than [p. 48] 1 mm high, colonies sometimes almost smooth in the centre, at first greyish brown, later mostly becoming dark grey. Reverse brownish grey, slightly zonate, sometimes blackish towards the margin. Exudate and odour absent. Submerged hyphae rather compact, sometimes fasciculate; two types of hyphae present: hyaline, smooth- and thin-walled hyphae mostly about 1-2 µm wide, and brown, smooth- and slightly thick-walled hyphae mostly about 3-5 µm wide. Aerial hyphae loose or fasciculate. Conidiogenous cells usually arising orthotropically from undifferentiated, more or less fasciculate hyphae, or plagiotropically in the apical regions of not or slightly differentiated hyphae, often also in terminal position, linear, continuous, rarely with a transverse septum, widest (1.7-2.5 µm) at or just above the base, tapering towards the tip, basal part mostly about 15-50 µm long; apical part forming conidia by sympodial growth, leading to an irregular, strongly denticulate conidiiferous rachis, up to about 40 µm long; denticles blunt, about 1 µm long. The conidiogenous cell may proliferate at or somewhat below the apex and gives rise to another series of denticles or a conidiogenous cell. Conidia hyaline, smooth- and thin-walled, fusiform, with a pointed base, (4-)5-10(-15) x 1.5-2.5 µm. In cultures grown in petri-dishes formation of secondary conidia is rare.

 

 

Fig. 18. Ophiostoma piliferum. a. CBS 129.32, conidial apparatus. b-c. from various living cultures. b. conidiogenous cells; c. conidia. [p. 49]

 

Material examined

 

Herbarium specimens

 

Ceratostomella pilifera, neotype, ex herb. G. G. Hedgcock (BPI), culture on wood.

Ceratostomella coerulea in herb. BPI: FP-9066 (type), three envelops with cultures on sapwood of Pinus sylvestris, leg. E. Münch, München, W-Germany; FP-14392, cultures on 2% sugar cornmeal agar, leg. E. Münch, München, W-Germany, (let. G. G. Hedgcock, May 1910.

 

Living strains

 

CBS 125.32 sent by E. Melin.

CBS 129.32 isolated from bark of Pinus sp. by H. A. Diddens.

CBS 138.33 (+ mating type) and 139.33 (— mating type) isolated by C. J. Buisman.

CBS 158.74 sent as no. 10 and 6 other strains sent by J. Grinbergs, Valdivia, Chile.

 

Discussion

 

The typification of Ophiostoma piliferum was discussed by Hunt (1956). In the neotype collection (BPI) both the perfect and the imperfect state are well preserved. The ascospores are allantoid in side view, 3.5-5 x 0.7-1.3 µm. Hunt (1956) described them, a.o. after examining the same collection, as ‘bean-shaped to shaped like sections of an orange, 4-6 x 1-2 µm’; in the collections of Griffin (1968) they are ‘orange section shaped (. . .), 3.0-5.5 x 1.0-1.5 µm’. From these descriptions it appears that the variations of the ascospores overlap Ophiostoma stenoceras and O. piceae (Munch) H. & P. Sydow. Munch (1907) united several similar species in the ‘Pilifera-Gruppe’, which only could be distinguished by means of the imperfect states. Indeed the conidial states of the present species offer the best distinctive characters.

The perfect state of Ceratostomella schrenkiana Hedgcock is indistinguishable from O. piliferum; the species probably should be listed as a synonym. However, as no conidial state could be found in the type material (BPI), this could not be ascertained. The type collection of C. capillifera Hedgcock (BPI) is in a bad condition. No ascospores or conidia could be found; consequently its identity remains doubtful. Of C. pluriannulata Hedgcock only some old perithecia could be traced in the type collection (BPI). According to Lagerberg & al. (1927) the conidial state has short chains of conidia; a strain sent to the CBS by R. W. Davidson (CBS 136.56) was identified as Ophiostoma stenoceras. It is likely that in the above identifications of C. pluriannulata, too much attention has been paid to the annuli of the perithecial necks; the species is regarded here as doubtful.

Ceratocystis ambrosia Bakshi, listed as a synonym of Ophiostoma piliferum by Griffin (1968), has aRaffaelea-like conidial state, very similar to that of C. alba. It should be maintained as a separate species.

The conidial state of O. pilifera can be recognized by long, tapering, [p. 50] well differentiated conidiogenous cells, rather long, conspicuously denticulate conidiiferous rachids and fusiform, usually single conidia. Part of the sterile hyphae are brown, thick- and slightly rough-walled, even in 30-year old cultures. It is similar to the conidial state of O. ulmi (Buisman) Nannf., but can be distinguished by longer conidia and conidiiferous rachids and the absence of a Graphium-like conidial state. There is also some similarity with Sporothrix insectorum, which has shorter, guttuliform conidia. The species is reminiscent of Acrodontium simplex (Mangenot) de Hoog, especially when occasionally some differentiation and pigmentation of fertile hyphae occurs; it can be distinguished by the difference in shape and pigmentation of conidiogenous cells and conidia.

Good descriptions of the conidial state were given by Munch (1907), Lagerberg & al. (1927, both as Ceratostomella coerulea), and Goidánich (1936b).

 

 

17. Ophiostoma ulmi (Buisman) Nannf. — Fig. 19

 

Ceratostomella ulmi Buisman — Tijdschr. PlZiekt. 38: 1. 1932 Ophiostoma ulmi (Buisman) Melin & Nannf. — Svensk SkogsvFör. Tidskr. 32: 408. 1934 — Ceratocystis ulmi (Buisman) C. Moreau — Revue Mycol., Suppl. Colon. 17: 22. 1952.

 

Status conidialis: Graphium ulmi Schwarz — Meded. phytopath. Lab. Willie Commelin Scholten 5: 13. 1922 = Pesotum ulmi (Schwarz) Crane & Schoknecht — Am. J. Bot. 60: 348. 1973.

 

Colonies in vitro attaining a diameter of 30-52 mm in 10 days, at first smooth, usually soon becoming finely floccose, especially towards the margin, slightly zonate, locally with tufts of Graphium-like synnemata; occasionally remaining smooth; at first pale citron yellow, later becoming whitish or greyish, locally brownish. Reverse cream coloured or pale citron yellow, often locally grey. Exudate and odour absent. Submerged hyphae hyaline, occasionally pale brown, smooth- or sometimes rough-walled, usually thin-walled, 1-2.5(-3) µm wide, intermixed with strongly septate hyphae of about 3-8 µm wide. Aerial hyphae, if present, thinner than the submerged hyphae, loose or slightly fasciculate. Conidiogenous cells scattered, arising orthotropically from undifferentiated, loose or fasciculate hyphae, often also integrated in short side branches, sometimes in terminal position, subcylindrical to linear, occasionally acicular, mostly about 10-30 µm long, about 1.5-2(-2.5) µm wide in the basal part, in the aerial mycelium usually somewhat narrower; apical part forming conidia by sympodial growth, consisting of a slightly swollen (up to 4 µm) cluster of conidium-bearing denticles or a short conidiiferous rachis; denticles usually short, blotch- or scar-like, sometimes subcylindrical, 0.3-1 µm. The conidiogenous cell may proliferate at or somewhat below the apex and give rise to another cluster of denticles, occassionally to another conidiogenous cell [p. 51]   

 

 

Fig. 19. Ophiostoma ulmi, from living cultures. a-b. Sphorothrix state. a. conidiogenous cells; b. conidia. c-e. Craphium state. c. synnemata; d. conidia; e. young conidiogenous cells. [p. 52]

 

Conidia hyaline, smooth- and thin-walled, continuous, fusiform, with a pointed base, 4-6(-7) x 1.5-2.5 µm, solitary or rarely in short chains. Liberated conidia may swell and give rise to a series of smaller, ellipsoidal secondary conidia. In most isolates light brown synnemata of about 800 µm high are present, loose, flexuose, widened apically by a hymeniform layer of linear, sympodial conidiogenous cells, producing honey-coloured, slimy masses of subhyaline, oblong conidia, 3.5-5(-6.5) x 1.5-2(-3) µm. A description of the synnematal state was provided by Schwarz. (1922, as Graphium ulmi), Goidánich (1936a), Clinton & McCormick (1936, as Ceratostomella ulmi), Crane & Schoknecht (1973, as Pesotum ulmi), and Harris & Taber (1973, as Ceratocystis ulmi).

 

Material examined

 

Herbarium specimens

 

Graphium ulmi, type, ex herb. A. van Luyk (U), culture on branch of Ulmus, M.B. Schwarz, Utrecht, 1920.

Ceratocystis ulmi in herb. CBS: three envelops with cultures on wood of Ulmus, Baarn, March-April, 1963, isol. V. Tchernoff; culture on wood of Ulmus, June, 1963, isol. F. W. Holmes; large collections of cultures on branches of Ulmus, Baarn, May, 1971, isol. F. W. Holmes.

 

Living strains

 

CBS 115.47 and 148.53 sent by J. C. Went, isolated from Ulmus.

CBS 151.55 and 152.55 sent by H. M. Heybroek, isolated from Ulmus.

CBS 102.63 (= IMI 101,223) and CBS 103.63 (= IMI 101,224) isolated from Ulmus x hollandica Mill. cv. ‘Belgica’, Naarden, by F. W. Holmes and H. M. Heybroek, Sept., 1962.

CBS 104.63 and 105.63 isolated by V. Tchernoff from Ulmus, Amsterdam; CBS 106.63 from Ulmus x hollandica cv. ‘Bea Schwarz’, Baarn; CBS 107.63 from Ulmus, Barsingerhorn.

CBS 374.67 isolated by H. Rebel from Ulmus wallichiana Planch., coll. H. M. Heybroek, Baba Reshi, Kashmir, India.

CBS 427.71 isolated by F. W. Holmes from Ulmus x hollandica cv. ‘Belgica’, Doorwerth.

 

Discussion

 

Ophiostoma ulmi is a common pathogen on several species of Ulmus in the Northern Hemisphere. Schwarz (1922) was the first to recognize the causative agent of the Dutch elm disease as a filamentous fungus, and described it as Graphium ulmi. The perfect state was discovered and fully described by Buisman (1932); original material is not known to exist any more. A vast number of studies of the disease has appeared since 1922; many references are given e.g., by Goidánich (1936a),Fransen (1939) and Elgersma (1969).

In pure culture Ophiostoma ulmi can be recognized by spreading, rather flat colonies (Walter, 1937), often with a citron yellow reverse. Under standard conditions usually no perithecia are formed; methods to induce [p. 53] formation of a perfect state are described by Shafer & Liming (1950), Rosinski (1958) and Holmes (1970). A synnematal form is usually present. Often the synnemata are loose, Verticicladiella-like (Fig. 19e), differing from the Sporothrix-state, which may be present as well, mainly by its retrogressive growth and by absence of conidium-bearing denticles. The Sporothrix state was present in all strains examined, often being more abundant when few synnemata were formed. It is similar to that of Ophiostoma piliferum; the differences are discussed on p. 50. Ceratocystis perfecta Davidson is also similar, but can be distinguished by its short chains of conidia — though occasionally these may also occur in O. ulmi (Crane & Schoknecht, 1973). Yeast-like budding of detached conidia was reported by Schwarz (1922), Goidànich (1936a) and Georgescu & Orenski (1957).

Ouelette & Gagnon (1970) described a small typeof conidia inside hyphal cells (microendospores), which were thought to be liberated by local lysis of the wall. In their interpretation of some processes of conidium ontogeny however they sometimes confused endoconidia with budding cells and the Sporothrix conidial state.

 

 

18. Ophiostoma multiannulatum (Hedgcock & Davidson) v. Arx

 

Ceratostomella multiannulata Hedgcock & Davidson in Davidson — J. agric. Res. 50: 797. 1935 = Ophiostoma multiannulatum (Hedgcock & Davidson) v. Arx — Antonio van Leeuwenhoek 18: 211. 1952 Ceratocystis multiannulata (Hedgcock & Davidson) Hunt — Lloydia 19: 40. 1956.

 

Discussion

 

The species is characterized by large, dark brown protuberant cells on the perithecial bases; the wall of the perithecium consists of a network of dark, rather wide hyphae. In addition, evident annuli occur along the necks, which may be verylong, up to 1 mm.

The type material (BPI) consists of a dried culture, on which both the perfect and the conidial state are more or less recognizable. The conidiogenous cells are of about the same shape and size as in Ophiostoma stenoceras; the elongate, fusiform conidia, which usually arise in short chains, are distinctive. For a new description of this state, too little fertile structures were found. A subculture of the type, CBS 124.39, has become sterile. A second culture, CBS 139.36, was sent by C. T. Andrus in 1936; probably this strain was isolated by K. W. Davidson. It did not produce perithecia any more. Its Sporothrix state is quite different from the type strain, but very similar to Ophiostoma piceae. [p. 54]

 

 

Fig. 20Ophiostoma perfectum, CBS 636.66. a-d. Sporothrix state. a. conidial apparatus; b. conidiogenous cells; c. primary conidia; d. secondary conidia. e-f. Graphium state. e. synnemata; f. conidia.

 

 

19. Ophiostoma perfectum (Davidson) de Hoog, comb. nov. — Fig. 20

 

Ceratocystis perfecta Davidson — Mycologia 50: 665.1958 (basionym).

 

Colonies in vitro attaining a diameter of 18 mm in 10 days, appearing velvety to finely funiculose, flocculose towards the margin, usually less than 1 mm high, white, later becoming pale yellowish grey, in the marginal region often becoming brownish by abundant formation of perithecia or synnemata. Reverse yellowish, locally brownish. Some hyaline exudate may be present; odour absent. Submerged hyphae hyaline, locally dark brown, smooth- or sometimes rough-walled, thin- or rather thick-walled, 1-4 µm wide, loose. Aerial hyphae hyaline, often very rough-walled by uncoloured incrustration, usually somewhat thinner than in the submerged mycelium, often forming fasciculi, from which the conidiogenous cells arise orthotropically; part of the hyphal cells may be swollen. Conidiogenous cells scattered, arising orthotropically from undifferentiated, loose or [p. 55] fasciculate hyphae, often also integrated in short side branches, sometimes in terminal position, acicular to cylindrical, widest at the base or somewhat above, gradually tapering towards the tip, continuous or septate, each cell about 12-35 µm long, about 1.5-3 µm wide near the base; apical part forming conidia by sympodial growth, consisting of a small cluster of conidium-bearing denticles; denticles sharp, usually blotch-like, about 0.5 µm long. The conidiogenous cell sometimes proliferates at or somewhat below the apex, forming a new cluster of denticles or a conidiogenous cell. Conidia hyaline, smooth- or rough-walled, thin-walled, fusiform, with a pointed base, continuous, rarely one-septate, 6-12 x 2-2.5 µm, often giving rise to one or several short series of secondary conidia. In the examined culture light to red brown synnemata of about 500 µm high were present, gradually widening upwards, apically with a hymeniform layer of linear, sympodial conidiogenous cells, producing slimy masses of hyaline, oblong conidia, 3.5-4.5 µm long, which slightly taper towards the base.

 

Material examined

 

CBS 636.66, type culture, isolated by R. W. Davidson from Picea engelmannii, Fort Collins, Colorado, January, 1956.

 

Discussion

 

In the type culture no perithecia were formed any more. Davidson (1958) did not discuss the relation of the species to other species described in Ophiostoma; from the diagnosis no differences from the ‘Pilifera-Gruppe’ can be abstracted. Ophiostoma ulmi is also similar, but can be distinguished by the small number of ostiolar hyphae, which are not attenuated but often inflated at the tips, and by the larger, crescent-shaped ascospores.

The best characters for identification can be found in the conidial state. It is reminiscent of O. piliferum, but differs by the absence of denticulate rachids and by the occurrence of a Graphium-like conidial state. The species also resembles O. piceae, but is distinct due to the smaller conidiogenous cells with blotch-like denticles, and the smaller conidia of the Graphium state. Davidson (1958) only mentioned the presence of the Sporothrix state and did not observe any Graphium-like synnemata.

 

 

20. Ophiostoma piceae (Munch) H. & P. Sydow — Fig. 21

 

Ceratostomella piceae Münch — Naturw. Z. Forst- u. Landw. 5: 547. 1907 Ophiostoma piceae (Münch) H. & P. Sydow — Annls mycol. 17: 43. 1919 = Ceratocystis piceae (Münch) Bakshi — Trans. Br. mycol. Soc. 33: 113. 1950.

Ceratostomella fagi Loos — Arch. Mikrobiol. 3: 376. 1932 = Ophiostoma fagi (Loos) [p. 56] Melin & Nannf. — Svensk SkogsvFör. Tidskr. 32: 408. 1934 = Ceratocystis fagi (Loos) C. Moreau — Revue Mycol., Suppl. Colon. 17: 22. 1952.

Ceratostomella catoniana Goidànich — Atti Accad. naz. Lincei Re., Ser. 6, 21: 199. 1935 = Ophiostoma catonianum (Goidànich) Goidànich — Boll. Staz. Patol. veg. Roma, N. Ser., 15:132. 1935 = Ceratocystis catoniana (Goidànieh) C. Moreau — Revue Mycol., Suppl. Colon. 17: 22. 1952.

Ophiostoma floccosum Mathiesen — Svenska bot. Tidskr. 45: 219. 1951 = Ceratocystis floccosa (Mathiesen) Hunt — Lloydia 19: 36. 1956.

 

Status conidialis: Graphium pirinum Goidànich — Boll, Staz. Patol. veg. Roma, N. Ser., 15: 132. 1935.

Hyalodendron pirinum Goidànich — Boll. Staz. Patol. veg. Roma, N. Ser., 15: 136. 1935.

Pesotum piceae Crane & Schoknecht — Am. J. Bot. 60: 348. 1973.

 

 

Fig. 21. Ophiostoma piceae, from living cultures. a-c. Sporothrix state. a. conidiogenous cells; b. primary conidia; c. secondary conidia. e-f. Graphium state. e. synnemata; f conidia; g. lateral conidia.

 

Colonies in vitro attaining a diameter of 14-22 mm in 10 days, floccose or lanose, rather flat, occasionally remaining smooth, often locally with tufts of Graphium-like synnemata; at first white, later often becoming greyish or pale brownish, or with blackish zones or sectors by abundant formation of synnemata or perithecia. Reverse uncoloured or pale greyish [p. 57] brown. Some hyaline exudate may be present; odour absent. Submerged hyphae hyaline, occasionally pale brown, smooth-walled, thin- or some-times slightly thick-walled, 1-3(-4.5) µmwide. Aerial hyphae, if present, thinner than the submerged hyphae, loose or slightly fasciculate. Conidiogenous cells scattered, arising orthotropically from undifferentiated hyphae, often also in terminal position or integrated in short side branches, subcylindrical to linear, variable in shape and size, usually widest in the basal region and slightly tapering towards the tip, mostly about 30-50 µm long, about 1.5-2.5 µmwide in the basal part, in the aerial mycelium usually somewhat narrower; apical part forming conidia by sympodial growth, consisting of a not or slightly swollen (up to 3.5 µm) cluster of conidium-bearing denticles; denticles cylindrical, rather robust, usually 0.7-1.5 µm long. The conidiogenous cell often proliferates at or somewhat below the apex, by which the first formed conidia become scattered alongside the apical region of the conidiogenous cell; after formation of the first cluster of denticles it may give rise to another cluster or a conidiogenous cell, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, fusiform, with a pointed base, continuous; conidia of first order rarely one-septate, mostly about 8-15 x 2-2.8(-3.5) µm, usually giving rise to one or several short series of smaller, secondary conidia. When older hyaline, rather thin-walled, subglobose or obovate lateral blastoconidia (about 2.5-4 µm in diameter) may be present. In fresh isolates light to mid brown synnemata of about 500 µm high are present, widened apically to a hymeniform layer of linear, sympodial conidiogenous cells, producing slimy masses of subhyaline, oblong conidia, 3-5.5 x 2-2.5 µm, which slightly taper towards the truncate base. A description of the synnematal state is provided by Munch (1907, as Ceratostomella piceae), Goidànich (1935, as Graphium pirinum), Crane & Schoknecht (1973, as Pesotum piceae) and others.

 

Material examined

 

Herbarium specimens

 

Ceratostomella piceae in herb. BPI: Forest Pathology 14395, dried culture on wood, isolated from sapwood of Picea abies (L.) Karst. by E. Münch, München, W-Germany; Forest Pathology unnumbered, dried culture on wood, isolated from sapwood of Picea abies by E. Münch, Bonn, W-Germany.

 

Living strains

 

CBS 108.21, type culture of Ceratostomella piceae, sent by E. Münch, 1921.

CBS 236.32, type culture of Ceratostomella fagi, isolated by W. Loos from Fagus sylvatica L., W-Germany.

CBS 263.35, type culture of Ceratostomella catoniana, isolated by G. Goidànich from Pyrus communis L., Italia, 1934.

CBS 142.37 and 143.37, sent by Botanisches Institut, Hannover-Münden, W-Germany.

CBS 153.54 isolated from brown spots on paper pulp, Norway, sent by L. Anker. [p. 58]

CBS 180.69 isolated from Picea sitchensis (Bong.) Carr, Cam Forest, County Atrim, N-Ireland, September 1968.

CBS 799.73 isolated from wood, Sweden, sent by A. Mathiesen-Käärik as Ceratocystis floccosa.

 

Discussion

 

The ascigerous state of Ophiostoma piceae is very similar to that of O. piliferum and some other species of the Pilifera-Gruppe’ (Munch, 1907). Lagerberg & al. (1927) and Hunt (1956) considered the short ostiolar hyphae as an important difference with O. piliferum; according to the latter author they are 10-25(-40)µm in O. piceae, whereas in O. piliferum they are 20-65µm. However, in some CBS-cultures of O. piceae the average length of the ostiolar hyphae is about 40 µm; it was impossible to distinguish these cultures from CBS 139.50, 104.66 and 360.71, which were identified as O. stenoceras, by comparing the perfect states only. Other authors (Münch, 1907;Nisikado & Yamauti, 1935; Griffin, 1968) distinguished the present species by means of the Graphium-like synnemata. As also the Sporothrix state is proved here to differ from the conidial state of Ophiostoma piliferum and from Sporothrix schenckii, O. piceae is considered here as a separate species, which can be recognized by the characters of both conidial states only.

The Sporothrix state of Ophiostoma piceae is characterized by rather long and wide conidiogenous cells, with an apical group of robust, often cylindrical conidium-bearing denticles. The conidia are rather long, fusiform; short, often branched chains of blastoconidia (Cladosporium type, cf. Hunt, 1956; Hyalodendron type, cf. Goidànich, 1935)are very common.

The names of the conidial states of the present species are somewhat confusing. Goidànich (1935) described both states separately as Graphium pirinum and Hyalodendron pirinum respectively, whereas Crane & Schoknecht (1973) described them jointly as Pesotum piceae.

Unfortunately in only one of the CBS-strains, 142.37, were all perfect and conidial states present. In the type culture, CBS 108.21, the Sporothrix state was well recognizable; its perfect state and Graphium-like synnemata were present in the dried type specimen at BPI. Representative cultures of both Graphium and Sporothrix state are CBS 143.37 and 180.69. CBS 153.54 formed perithecia in pure culture, but had lost the Graphium-like conidial state; it could now only be distinguished from Ophiostoma piliferum by its Sporothrix state.

The original culture of Ceratostomella fagi, CBS 236.32, is in rather bad condition; only a Sporothrix state, very similar to that of Ophiostoma piceae, could be recognized. Loos (1932)already regarded the conidial states of C. fagi as nearly identical to those of O. piceae. According to the diagnosis, the differences between the perfect states of both species are also very slight. Hunt (1956) suspected C. fagi to be a synonym of O. piceae; this opinion is shared here. [p. 59].

Goidànich (1935) described both conidial states of Ceratostomella catoniana as separate species, resp. Graphium pirinum and Hyalodendron pirinum; all names are based upon the same specimen. This strain, CBS 263.35, produced neither perithecia, nor synnemata. The Sporothrix state (Hyalodendron pirinum) is indistinguishable from the conidial state of Ophiostoma piceae. Comparing the original description of C. catoniana with O. piceae, no differences can be found between the Graphium-like conidial states of both species. The perfect state of C. catoniana differs only by its slightly longer ostiolar hyphae (compare Hunt, 1956); this character is considered here as insufficient for separation of both species.

Hunt (1956) and Griffin (1968) mentioned the possible synonymy of Ophiostoma piceae and O. floccosum. A representative strain of the latter species, kindly sent by Dr. A. Mathiesen-Käärik, has lost the ability to produce perithecia. Comparing the diagnoses of both species, as given by Hunt (1956) and Mathiesen (1951) respectively, it can be concluded that the perfect states are identical. From the cultures no difference could be found between the Sporothrix states of both species. Some minor differences are observed in the Graphium states: the synnemata of O. floccosum are somewhat looser, more cinnamon brown, and the conidia are darker, ochraceous in mass. These differences are, however, regarded here as insufficient to base a separate species upon.

Ceratocystis populina Hinds & Davidson is closely related to Ophiostoma piceae. In the type culture, CBS 212.67, no mature perithecia are formed any more. According to Hinds & Davidson (1967) Ceratocystis populina should differ from other species described in Ceratocystis auctt. mainly by the perithecial bases, which were ornamented with short conical spines. In this respect the species resembled C. moniliformis (Hedgcock) C. Moreau. Some other characteristics of C. populina, such as length of the perithecial necks and presence of annuli, are too variable to distinguish the species from Ophiostoma piliferum and O. piceae. In its cultural characters and the morphology of the conidial state the species is identical to Ophiostoma piceae, except for the absence of Graphium-like synnemata. In some strains of O. piceae however (viz. CBS 120.31, 139.51 and 153.54) this type of conidial state is lost too.

 

 

21. Ophiostoma narcissi Limber — Fig. 22

 

Ophiostoma narcissi Limber — Phytopathology 40: 493. 1950 = Ceratocystis narcissi (Limber) Hunt — Lloydia 19: 50. 1956.

 

Colonies in vitro attaining a diameter of 7-17 mm in 10 days, appearing thinly floccose, about 1 mm high, sometimes smooth, at first white, later becoming pale grey, often with many dark zones by abundant formation of perithecia. Reverse uncoloured or very pale grey, occasionally cream coloured in the centre. Exudate and odour absent. Hyphae hyaline, [p. 60] sometimes locally pigmented, smooth- and thin-walled, 1-2.5 µm wide. Conidiogenous cells scattered, arising orthotropically from undifferentiated hyphae, often also in terminal position or integrated in short side branches, continuous, later sometimes with a transverse septum, widest near the base and slightly tapering towards the tip, about 20-50 µm long and about as wide as the supporting hypha, 1.2-2.3 µm; apical part forming conidia by sympodial growth, consisting of a slightly swollen (up to 4 µm) cluster of conidium-bearing denticles; denticles blunt or blotch-like, usually about 0.5 µm long. The conidiogenous cell may proliferate at or somewhat below the apex and give rise to another conidiogenous cell. Conidia hyaline, smooth- and thin-walled, fusiform, sometimes flattened at one side, with a pointed base, 4-6.5(-9) x 2-5 µm. Hyaline, subglobose blastoconidia and secondary conidia (about 2.5 µm in diameter) are abundantly formed laterally and terminally on undifferentiated hyphae, resp. on detached conidia.

 

 

Fig. 22. Ophiostoma narcissi, from living cultures. a. conidiogenous cells; b. sympodial conidia; c. lateral conidia.

 

Material examined

 

CBS 138.50 type culture, isolated by R. F. Olsen from Narcissus sp., Netherlands, January 1946, sent in 1950 by D. P. Limber.

CBS 414.72. isolated by B. H. H. Bergman, Lisse, from Narcissus sp.

CBS 774.73, isolated by P. J. Muller, Lisse, from Narcissus sp.

 

Discussion

 

The perfect state can be recognized by the short necks of the perithecia, and by the broadly ellipsoidal ascospores (Laundon, 1973); the fungus is host specific on Narcissus species. The conidial state is very similar to that of Ophiostoma stenoceras, but differs by the somewhat narrower fusiform conidia and by the smaller diameter of the lateral blastoconidia. [p. 61]  

 

 

Fig. 23. Ophiostoma longirostellatum, CBS 134.51. a. conidiogenous cells; b. conidia.

 

 

22. Ophiostoma longirostellatum (Bakshi) v. Arx & Müller — Fig. 23

 

Ceratocystis longirostellata Bakshi — Mycol. Pap. 35: 8. 1951 Ophiostoma longirostellatum (Bakshi) v. Arx & Müller — Beitr. KryptFl. Schweiz 11-1: 395. 1954.

Ceratocystis californica DeVay & al. — Mycologia 60: 639. 1968.

 

Colonies in vitro attaining a diameter of 20-25 mm in 10 days, flat, later becoming floccose or finely funiculose, up to 1 mm high, white, sometimes with some shades of grey. Reverse uncoloured, soon becoming brownish grey. Exudate and odour absent. Submerged hyphae hyaline, smooth- and thin-walled, usually 1-1.5 µm wide, rather irregular, often intermixed with more regular, pale brown hyphae of about 1.5-3(-4.5) µm wide. Aerial hyphae, if present, hyaline, usually somewhat thinner, loose, occasionally somewhat fasciculate, in the latter case mostly sterile. Conidiogenous cells hyaline or subhyaline, scattered, usually arising orthotropically from undifferentiated hyphae, often also in terminal position or integrated in short side branches, continuous or becoming septate, straight or flexuose, variable of shape and size, often irregular, acicular to linear, widest at the base and tapering towards the tip, often wider than and not sealed off from the supporting hypha, (5-)15-35 x 1.5-2.5 µm; apical part forming conidia by sympodial growth, consisting of a cluster of conidium-bearing denticles or an irregular conidiiferous rachis, not or only slightly differentiated from the basal part, sometimes with intercalary sterile parts; denticles rather blunt, subcylindrical, (0.5-)1-1.5(-2.5) µm long. The conidiogenous cell often becomes intercalary by secondary proliferation. Conidia hyaline, smooth- and thin-walled, subulate or fusiform, sometimes slightly curved, with a pointed base, 4.5-9.5(-15) x 1.5-3 µm, often giving rise to a short series of smaller, secondary conidia or occasionally with a secondary conidiiferous rachis. Liberated conidia often become large, inflated, and bud with short series of smaller, ellipsoidal conidia. [p. 62]

 

Material examined

 

CBS 134.51, type culture of Ceratocystis longirostellata, isolated by B. K. Bakshi from Quercus sp.

CBS 421.69 sent by J. J. Taylor under no. UM-805.

CBS 796.73 (= ATCC 18392), type culture of Ceratocystis californica, isolated from Prunus domestica L., Onsott Ranch, Gridley, California, USA, August, 1963.

 

Discussion

 

Ophiostoma longirostellatum is very similar to the species belonging to the ‘Pilifera-Gruppe’. It has slightly narrower and longer, allantoid ascospores (about 3-5.5 x 1-1.5 µm), but even here is a considerable overlap. Hunt (1956) listed the species as a synonym of Ceratostomella capillifera. In the type collection (BPI) neither ascospores nor conidia could be traced, which made this statement impossible to verify.

The species can be recognized by the conidial state, especially by the acicular shape of the conidiogenous cells. In young cultures the immature conidiogenous cells are characteristic, having no basal septa and being considerably wider than the supporting hyphae.

 

 

Fig. 24. Ophiostoma nigrocarpum, CBS 637.66 and 638.66. a. conidiogenous cells; b. conidia.

 

 

23. Ophiostoma nigrocarpum. (Davidson) de Hoog, comb. nov. — Fig. 24

 

Ceratocystis nigrocarpa Davidson — Mycopath. Mycol. appl. 28: 276. 1966 (basionym)

 

Colonies in vitro attaining a diameter of 20-25 mm in 10 days, appearing smooth, flat, sometimes slightly slimy, later finely floccose, grey, often [p. 63] locally grey to blackish. Submerged hyphae hyaline, occasionally pale brown, smooth- and thin-walled, 1.5-3 µm wide, rather loose. Aerial hyphae, if present, usually somewhat thinner. Conidiogenous cells scattered, arising terminally or laterally from undifferentiated hyphae, often intercalary or integrated in short side branches, continuous or septate, if laterally often not sealed off from the supporting hypha, straight or flexuose, rather irregular of shape, cylindrical, often slightly swollen, sometimes tapering towards the tip, variable in size, each cell usually about 10-25 µm long and 1.5-2.5 µmwide; apical part forming conidia by sympodial growth, consisting of a small cluster of conidium-bearing denticles or a short, irregular conidiiferous rachis, often not or only slightly differentiated from the basal part; denticles blunt, short cylindrical, about 0.5-1.5 µmlong. The conidiogenous cell often becomes intercalary by secondary proliferation. Conidia hyaline, smooth- and thin-walled, obovoidal to broadly ellipsoidal, sometimes subcylindrical, basally rounded, with an inconspicuous scar, 3.5-5 x 1.5-2.5 µm. Often liberated conidia become large, swollen and give rise to a series of ellipsoidal secondary conidia.

 

Material examined

 

CBS 637.66, type culture, isolated from Abies sp. near McCall, Idaho, USA, July 1962, sent by K. W. Davidson under no. 152.

CBS 638.66 isolated from Pseudotsuga douglasii Carr. near McCall, Idaho, USA, July 1962, sent by R. W. Davidson under no. 155-B.

 

 

Fig. 25. Ophiostoma microsporum, CBS 420.69 and 440.69. a. fertile hyphae; b. conidia. [p. 64]

 

 

24. Ophiostoma microsporum (Davidson) v. Arx — Fig. 25

 

Ceratostomella (Ophiostoma) microspora Davidson — Mycologia 34: 650. 1942 [not Ceratostomella microspora Ell. & Ev. — Acad. Nat. Sci. Phil. Proc. 45: 444. 1893] = Ophiostoma microsporum (Davidson) v. Arx — Antonie van Leeuwenhoek 18: 211. 1952 = Ceratocystis perparvispora Hunt — Lloydia 19: 46. 1956 (name change).

 

Colonies in vitro attaining a diameter of 10 mm in 10 days, appearing smooth, flat, sometimes slightly slimy, occasionally with some small tufts of aerial mycelium, whitish, later sometimes with some shades of grey. Reverse pale grey or cream coloured. Submerged hyphae hyaline, smooth- and thin-walled, 1-3 µm wide, rather loose. Aerial hyphae, if present, usually somewhat thinner, loose or fasciculate. Conidiogenous cells scattered, arising terminally or laterally from undifferentiated hyphae, often intercalary or integrated in short side branches, continuous or septate, if laterally often not sealed off from the supporting hypha, straight or flexuose, rather irregular of shape, cylindrical, often slightly swollen, some-times tapering towards the tip, variable in size, each cell usually about 8-13 µm long and 1.5-2 µm wide; apical part forming conidia by sympodial growth, consisting of a small cluster of conidium-bearing denticles or a short, irregular conidiiferous rachis, often not or only slightly differentiated from the basal part; denticles blunt, often flattened and scar-like, usually less than 1 µm long. The conidiogenous cell often becomes intercalary by secondary proliferation; frequently conidia are formed on solitary or occasionally clustered denticles on intercalary hyphal cells. Conidia hyaline, smooth- and thin-walled, reniform, sometimes ellipsoidal, basis rounded, with an inconspicuous scar, 4-5 x 1.5-2 µm. Locally, large, swollen, ellipsoidal conidia give rise to a series of secondary conidia, which often are oblong, straight or slightly curved.

 

Material examined

 

CBS 420.69 sent by J. J. Taylor under no. UM-809.

CBS 440.69 (=ATCC 22392) isolated from Quercus sp., associated with Endothia parasitica (Murril) Anderson, Williamsburg, Virginia, USA, 1963.

 

 

Discussion

 

No type material was available for study; Hunt (1956) suspected it to be lost. A second collection made by Davidson was sent to the CBS in 1969. Except the absence or scattered occurrence of aerial mycelium, which was said to be abundant by Davidson (1942), it fits the diagnosis in its colony characters and morphology of the conidial state. None of the CBS strains produced any perithecia. [p. 65]

 

 

Fig. 26. Sporothrix luteoalba, CBS 208.48 and 209.48. a. conidiogenous cells; b. conidia.

 

 

25. Sporothrix luteoalba de Hoog, sp. nov. Fig. 26

 

Coloniae in vitro post to dies 2-3 mm, leves, cremeae ad ochraceae. Hyphae hyalinae, glabrae, tenuiter tunicatae. Cellulae conidiogenae in hyphis non differentiatis laxe oriundae, saepe intercalares, forma sat irregulares, cylindraceae, circa 10-40 µm longae et 1.5-2.5 µm latae; pars apicalis incremento sympodiali conidia formans, ex rachi curta, irregulari consistens, non vel paulo ab parte basilari differentiata; denticuli obtusi. Conidia hyalina, glabra, reniformia ad allantoidea, (4-)5-6(-7.8) x 1-1.5(-2.5) µm. Status perfectus ignotus.

Typus CBS 209.48 ab R. Kühner missus.

 

Colonies in vitro attaining a diameter of 2-3mm in 10 days, appearing smooth, flat or slightly elevated, cream coloured to ochraceous. Reverse of the same colour. Exudate and odour absent. Submerged hyphae hyaline, smooth- and thin-walled, 1.5-3(-4) µm wide, forming a compact mycelium. Conidiogenous cells scattered, arising terminally or laterally from undifferentiated hyphae, often intercalary or integrated in short side branches, if laterally often not sealed off from the supporting hypha, straight or flexuose, rather irregular of shape, cylindrical, often slightly inflated, of variable size, about 10-40 µm long if terminally, 3-20 µm long if laterally, about 1.5-2.5(-3.5) µm wide; apical part forming conidia by sympodial growth, consisting of a cluster of conidium-bearing denticles or an irregular conidiiferous rachis, not or slightly differentiated from the basal part; denticles blunt, subcylindrical, 0.5-1.5 µm long. The conidiogenous [p. 66] cell may become intercalary by secondary proliferation. Conidia hyaline, smooth- and thin-walled, reniform to allantoid, sometimes ellipsoidal, with a rounded base, sometimes with a small hilum, (4-)5-6(-7.8) x 1-1.5 (2.5) µm. Detached conidia may swell and give rise to a series of secondary conidia or a short conidiiferous rachis. Perfect state unknown.

 

Material examined

 

CBS 208.48 and 209.48 (type culture), sent by R. Kühner as Femsjonia luteoalba Fr.

 

Discussion

 

The above strains were sent to the CBS as Femsjonia luteoalba [= F. peziziformis (Lev.) Karst.]. However, the Basidiomycete genus Femsjonia as monographed by MacNabb (1965), is characterized i.a. by large conidia, becoming tardily multi-septate; the mycelium consists of thick-walled hyphae with conspicuous clamp connections. In the present strains no clamp connections were observed.

Sporothrix luteoalba resembles the conidial state of Ophiostoma micro­sporum, but differs by the yellowish colonies, the somewhat larger conidiogenous cells and the conidia, which are longer, though usually of equal width. The conidial state of Ophiostoma nigrocarpum is also similar, but can be distinguished by the shape of the conidia. Another species with curved conidia is Sporothrix curviconia, which can be recognized by rapidly growing, white colonies, slender, tapering conidiogenous cells of regular shape and conidia with acute bases.

 

 

Excluded species of Sporothrix

 

 

26. Nodulisporium tuberum Fontana &. Bonfante ex de Hoog, sp. nov. — Fig. 27a-b

 

Sporothrix tuberum Fontana & Bonfante — Allionia 17: 12. 1971 (without indication of type material).

 

Coloniae in agaro maltoso 2% post 30 dies 20 mm diametro, velutinae, albae, deinde saepe pallide ochraceae. Hyphae hyalinae, glabrae vel rugulosae, 3-12 µm latae. Cellulae conidiogenae in hyphis non differentiatis laxe oriundae, ex parte basilari cylindracea, 20-40 µm longae et 3-4(-6) µm latae, et rachi longa, 2-3 µm lata, intervallis variabilibus hilis evidentibus praedita consistentes. Conidia hyalina, glabra, obovoidea ad ellipsoidea, 4.5-11 x3.5-5 µm. Status perfectus ignotus.

Typus CBS 234.73 ex Tuber sp., Torino, Italia, isolatus, ab A. Fontana missus. [p. 67]

 

 

Fig. 27. a-b. Nodulisporium tuberum, CBS 234.73.a. conidiogenous cells; b. conidia. c-d. Hansfordia parasitica, CBS 130.58. c. tip of conidiophore; d. conidia.

 

Colonies on 2%malt agar attaining a diameter of 20 mm in 30 days, appearing velvety, finely lanose towards the margin, white, later often becoming pale ochraceous. Reverse cream coloured. Exudate and odour absent. Submerged hyphae hyaline, smooth-walled, 3-12 µm wide. Aerial hyphae smooth- or slightly rough-walled, usually about 3-5 µm wide. Conidiogenous cells arising plagiotropically in the apical regions of undifferentiated hyphae, often in terminal position, consisting of a cylindrical or somewhat swollen basal part, mostly about 20-40 µm long and about 3-4(-6) µm wide, and a long cicatrized rachis, 2-3 µm wide, with conspicuous scars or flat denticles about 0.7-1.5 um wide at variable intervals. The conidiogenous cell may proliferate at the apex and give rise to another conidiiferous rachis or a conidiogenous cell, which in turn may become intercalary. Conidia hyaline, smooth- and thin-walled, obovoidal to ellipsoidal, sometimes pyriform or cylindrical, 4.5-11 x 3.5-5 µm. When older often strongly inflated hyphal cells occur.

 

 

Material examined

 

CBS 234.73, type culture, isolated from Tuber sp., Torino, Italia, sent by A. Fontana as Sporothrix tuberum.

 

Discussion

 

The present species was well described and depicted by Fontana & Bonfante (1971). Several strains were mentioned; unfortunately non of them was indicated as type. It is classified here in Nodulisporium because of the properties of the mycelium, and the conidia, which have truncate bases, leaving flat scars at liberation. The latter characteristic was considered to be of high taxonomical value in Nodulisporium by de Hoog (1973).

 

 

 Calcarisporiella de Hoog, gen. nov.

 

Coloniae incremento rapidiuscule, laxe floccosae, albae. Hyphae hyalinae, glabrae, tenuiter tunicatae, fragiles, laxissimae, saepe flexuosae. Cellulae conidiogenae in hyphis non differentiatis laxe vel gregatim oriundae, ex parte basilari paulo inflato, collo angusto praedita, et massula denticulorum cylindraceorum conidioferentium apicali consistens. Conidia continua, hyalina, glabra, tenuiter tunicata, ovoidea ad ellipsoidea. Status perfectus ignotus.

 

Species typica: Calcarisporium thermophilum Evans

 

Colonies growing moderately rapidly, appearing thinly floccose, white. Vegetative hyphae hyaline, smooth- and thin-walled, delicate, very loose, often flexuose. Conidiogenous cells scattered or in small groups, arising from undifferentiated hyphae, consisting of a somewhat inflated basal part with a narrow neck, and a small apical group of cylindrical conidium-bearing denticles. Conidia one-celled, hyaline, smooth- and thin-walled, ovoidal to ellipsoidal, with a rounded base. No perfect state was observed.

Descriptions are based on colonies growing on potato carrot agar at 30°C.

 

 

27. Calcarisporiella thermophila (Evans) de Hoog, comb. nov. — Fig. 28

 

Calcarisporium thermophilum Evans — Trans. Br. mycol. Soc. 57: 247. 1970.

 

Colonies in vitro attaining a diameter of 20 mm in 10 days, flocculose, up to 4 mm high, white. Reverse uncoloured or very pale yellowish. Some vinaceous exudate rarely produced (Evans, 1970); odour absent. Submerged hyphae hyaline, smooth- and thin-walled, delicate, 2-5 µm wide, often undulating or spirally coiled, very loose. Aerial hyphae usually somewhat thinner. Conidiogenous cells scattered or in pairs, arising orthotropically from undifferentiated aerial hyphae, continuous or rarely with a transverse septum, consisting of an inflated basal part, usually about 15-25 µm long, [p. 69] 1.5-2 µm wide at the basal septum, widest (2.5-3.5 µm around or above the middle, and a long, linear neck, about 20-35(-50)µm long, 0.8-1.5 µm wide; apical part forming conidia by sympodial growth, consisting of a small group of conidium-bearing denticles, sometimes leading to a short, curved or more or less geniculate denticulate rachis; denticles cylindrical, usually 3-5 µmlong and about as wide as the neck of the conidiogenous cell. Conidia hyaline, smooth- and thin-walled, ovoidal to ellipsoidal, base rounded, with a small scar or a flat hilum, 7-9(-11) x 4-6 µm. Perfect state unknown.

 

 

Fig. 28. Calcarisporiella thermophila, CBS 279.70. a. conidiogenous cells; b. conidia; c. inflated hyphal cell in culture at 45°C.

 

 

Material examined

 

CBS 279.70, type culture, isolated by H. C. Evans from coal spoil tips, Staffordshire, England, March 1968.

 

Discussion

 

The genus Calcarisporiella morphologically resembles some species of [p. 70] Sporothrix, but differs by its wide, undulating, fragile hyphae, the shape of the conidiogenous cells, the wide conidium-bearing denticles, and by the shape and size of the conidia. It is distinct from Calcarisporium owing to the same features as mentioned above, and to the absence of differentiated conidiophores, though some verticillate branching occurs. The conidium production is somewhat reminiscent of Candelabrella Rifai & R. C. Cooke and similar genera, in which the denticles are regularly cylindrical, and occur in loose groups. The conidia in this genus have relatively wide basal scars. The fungi with this type of conidia were listed by von Arx (1970) under the heading ‘genera with aleuriospores’.

Growth of Calcarisporiella thermophila occurs between 20° and 45°C, with an optimum at 40°C (Fig. 5). However, abundant sporulation occurs at 25-35°C; at 40°C and above sporulation decreases rapidly, and irregular hyphal swellings are formed, described as ‘chlamydospores’ by Evans (1970).

 

 

 Calcarisporium Preuss

 

Calcarisporium Preuss — Linnaea 24: 124. 1851 (not Calcarispora Marvanova & Marvan — Acta Mus. Silesiae, Ser. A, 12: 109. 1963).

 

Colonies growing moderately rapidly, appearing lanose, white. Vegetative hyphae hyaline, smooth- and thin-walled, loose. Conidiophores hyaline, smooth-walled, often slightly rough-walled at the base, erect, bearing in the upper part several whorls of conidiogenous cells. Conidiogenous cells elongate, widest near the base and gradually tapering towards the tip, apically with a cluster of long conidium-bearing denticles. Conidia continuous, hyaline, smooth- and thin-walled, obovoidal to fusiform. Black, subglobose sclerotia may be present.

 

Type species: Calcarisporium arbuscula Preuss

 

Discussion

 

Calcarisporium was described by Preuss (1851) with one species, C. arbuscula. It is characterized by hyaline, erect, verticillate conidiophores and sympodial conidium formation. In this sense the genus is monotypic.

Calcarisporium is closely related to Sporothrix. The most important criterium for recognition is the presence of verticillate conidiophores in C. arbuscula, especially on the natural substrate and in fresh isolates (Fig. 29a-b). On artificial media conidiophores of this type are usually lost after some years of cultivation, and the conidiogenous cells and often also the conidia are longer and narrower (Fig. 29d). Such cultures can only be distinguished from some Sporothrix species by the shape and size of the conidia and by the frequent occurrence of verticillate branching. [p. 71]

Pseudobotrytis Krzeminiwska & Badura differs from Calcarisporium by dark conidiophores, bearing clusters of inflated conidiogenous cells. Hans­fordia Hughes is distinct due to pigmented conidiophores and rather short, cylindrical conidiogenous cells, apically with some scattered conidium-bearing denticles; if the conidiogenous cells are tapering, long conidiiferous rachids are present. Nodulisporium Preuss differs by cylindrical, not taper­ing conidiogenous cells and Acrodontium de Hoog by the presence of long conidiiferous rachids.

 

 

Fig. 29. Calcarisporium arbuscula. a-c. from fresh culture. a. tip of conidiophore; b. conidiophore at low magnification; c. conidia. d. CBS 144.52 on oat-meal agar, tip of conidiophore.

 

 

28. Calcarisporium arbuscula Preuss — Fig. 29

 

Calcarisporium arbuscula Preuss — Linnaea 24: 124. 1851 (not sensu A. L. Smith — Trans. Br. mycol. Soc. 3: 121. 1908).

Verticillium beauverioides Vincens — Bull. Soc. bot. Fr. 63: 211. 1916.

Cladobotryum elegans Arnaud — Bull. trimest. Soc. mycol. Fr. 69: 298. 1953 (without Latin diagnosis).

Calcarisporium antibioticum Haller & Loeffler — Arch. Mikrobiol. 65: 184. 1969. [p. 72]

 

Discussion

 

Calcarisporium arbuscula is a common parasite on higher Basidiomycetes and Ascomycetes, occasionally occurring on wood (Sutton, 1973). Descriptions are provided by von Höhnel (1924) and Hughes (1951). The type collection (B) is too scanty for examination. According to Hughes (1951) there is little doubt about the identity of the species; his concept has become widely accepted.

Saccardo (1886) and Costantin (1888) mentioned a possible relationship with Sceptromyces Corda. Of the type species, S. ophizii Corda (=Cephalosporium sceptromyces Bon.), no material is available in PR. Lindau (1907) listed the species as a synonym of Aspergillus niger van Tieghem.

Tubaki (1955) suggested the synonymy of Calcarisporium arbuscula and Cladobotryum ternatum Corda var. binatum Preuss. However, after exam­ining the type material Gams & Hoozemans (1970) considered this variety to be identical with the conidial state of Hypomyces rosellus (Alb. & Schw. per Fr.) Tul.

In the Preuss herbarium (B) a specimen is deposited under the unpublish­ed name Calcarisporium actinocladioides. It consists of some young carpophores of a Hyaloscyphaceae, on which some hyaline hyphae, possibly belonging to C. arbuscula could be found. A collection under the name Calcarisporium arbuscula in the herbarium A. L. Smith (K) comprised a Nodulisporium sp., resembling the conidial state of Daldinia concentrica (Bolt. per Fr.) Ces. & de Not. (= Nodulisporium tulasnei Molliard). A discussion on this matter is given by Hughes (1951).

 

Doubtful or excluded species of Calcarisporium

 

Calcarisporium abietis Sutton — Mycol. Pap. 132: 23. 1973.

This species was well described and depicted by Sutton (1973). Because of the absence of differentiated conidiophores and the subulate conidio­genous cells, apically with a long rachis densely crowded with small denticles, it can be classified as Acrodontium abietis (Sutton) de Hoog, comb. nov. It can easily be recognized from other species of the Acrondontium-section by hyaline colonies and globose conidia.

The hyaline appearance suggest some similarity with the genus Sporothrix, e.g. the conidial states of Ophiostoma piliferum and O. ulmi; it differs, however, by the shape of the conidiogenous cells and the very thin rachids with minute conidium-bearing denticles.

 

Calcarisporium echinosporum Deighton & Pirozynski — Mycol. Pap. 128: 101. 1972.

In the type material (IMI 1136) the species occurred rather scarcely amongst several parasites on Meliola millettiae-rhodantae Hansf. & Deighton on leaves of Millettia thonningii. The conidiogenous cells are [p. 73] phialides, forming slimy, globose heads of spherical, smooth-walled conidia; the species is very similar to the conidial state of Calonectria cephalosporii Hansf. as described by Gams (1971).

 

Calcarisporium griseum Speg. — Mycet. argent., Ser. 2, p. 86. 1902.

The type material (LPS) consisted of a carpophore of a Phellinus sp., on which no imperfect fungus could be found. Concluding from the original description, possibly a Cladobotryum sp. was meant.

 

Calcarisporium indicum D. Rao & R. Rao — Curr. Sci. 33: 187. 1964.

No material of this species was available for study. From the description it can be concluded that it is similar to Calcarisporium parasiticum Barnett, which is more or less intermediate between the Griseum-section of Acrodontium, and Hansfordia Hughes. The diagnosis of C. indicum is insufficient to establish its identity.

 

Calcarisporium pallidum Tubaki — Nagaoa 5: 13. 1955. This species is indistinguishable from Sporothrix schenckii.

 

Calcarisporium parasiticum Barnett — Mycologia 50: 500. 1958.

There is much similarity between this species and some species of the Griseum-section of Acrodontium, e.g. A. griseum (Fassatiová) de Hoog. However, the conidia of Calcarisporium parasiticum are considerably larg­er, hyaline, obovate, and have a more or less rounded base (Fig. 27d). Also the conidiogenous cells are larger, the denticles are firmer. The above characters, and its occurrence as a hyperparasite on other fungi (mainly Ascomycetes, e.g. Dothiorella quercina Cke & Ellis) points to Hansfordia Hughes, as already mentioned by Barnett (1958). Thus it can be classified as Hansfordia parasitica (Barnett) de Hoog, comb. nov. It differs from all other species described in Hansfordia by its less strongly branched conidio­phores and the bottle-shaped conidiogenous cells.

 

Calcarisporium setiphilum Deighton & Pirozynski — Mycol. Pap. 128: 100. 1972.

This species was discussed on p. 32 of this study as Sporothrix setiphila.

 

Calcarisporium thermophilum Evans — Trans. Br. mycol. Soc. 57: 247. 1970.

By the shape of the conidiogenous cells and the conidiiferous rachids this species is very distinctive; a new genus is proposed on p. 68.

 

 

 Acknowledgements

 

The author is much obliged to Dr. J. A. von Arx for his help and criticism, and to Prof. Dr. K. Verhoeff for his help in preparing the manuscript. He is indebted to Prof. Dr. F. P. Jonker and Prof. Dr. F. A. Stafleu for advices concerning classification. He wishes to express his gratitude to Mme J. Nicot and to Dr. F. Mariat for their kind cooperation and for [p. 73] giving valuable suggestions, to Dr. G. A. de Vries for making the Latin diagnoses, and to Mr D. Yarrow for correcting the English text. Miss M. Th. Smith is acknowledged for her friendly help during the study of yeasts, and Miss J. Sytema for technical assistance.

 

 

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