KEYS TO THE MOEE IMPORTANT GENERA OF FUNGI IMPEFECTI 623 



Sporodochia more or less disk-shaped, not stalked. 



CylindrocoUa 

 Sporodochia sessile or short-stalked ; at the margin with bristles. 



Volutella^* 

 Conidia phragmosporous. 



Conidia straight, at the upper end somewhat thickened and angular. 



Heliscus 

 Conidia straight, elongate-cylindrical, not thickened at upper end. 



Bactridium 

 Conidia falcate-fusiform. 



Sporodochia conical or cushion-like, delicate; often parasitic upon insects. 



Microcera 

 Sporodochia extended, or large and cushion-formed, more often lacking, 

 the spores then arising from the mycelium. 



Fusarium 

 Conidia brown, rarely almost hyaline; sporodochia and usually the conidiophores 



brown. 

 Conidia one-celled. 



Sporodochia without hairs or bristles. 



Sporodochia cushion-like or tuberculate or almost spherical, black. 



Conidiophores short; conidia globose; parasites, or more often, sapro- 

 phytes. Epicoccum 

 Conidiophores longer, mostly branched; conidia ovoid to elongate, some- 

 times curved. Saprophytes. Strumella 

 Conidiophores slender or clavate at the apex; conidia ovoid, elongate, or 

 pyriform, borne singly or in chains. 



Epidochium 

 Sporodochia flat, not convex; conidiophores cylindrical, conidia ovoid, 

 elongated, or rod-shaped. Hymenopsis 



Sporodochia with hairs or bristles. 



Hairs black, marginal. Chaetostromn 



Hairs hyaline, marginal. Myrothecium 



Conidia phragmosporous. 



Conidia single on conidiophores. Exosporium 



Conidia in chains on conidiophores. Trimmatostroma 



Conidia spherical, reticulately marked, each areola representing a distinct cell. 



Epicoccum 



(some species) 



Key to a Few Genera of Order Mycelia Sterilia 



Sclerotium-like bodies produced. 



Sclerotia flattened, usually on surface of host, connected by brown fibrillose 

 hyphae. Imperfect forms of Basidiomyceteae. Rhizoctonia 



Sclerotia round, ellipsoid or elongated, often more or less flattened on lower 

 surface, often several growing together into a compound structure; internally 

 firm and usually white, with a definite, black, brown, or light brown cortical 

 layer. Many species are imperfect forms of Aseomyceteae, others of Basidio- 

 myceteae. Sclerotium 



^* Parasitic species when young may be confused with CoUetotrichum. 



