Pound and Clements: north American hyphomycetes. 659 



IlELICOMYCES MICROSCOPICUS ( ELL.) 



Helicosporium microscopicum Ell. Bull. Torr. Bot. Club. 9:98. 1882. 



IlELICOMYCES MUELLERI ( CORDA) . 



Helicoma muelleri Corda. Ic. Fung. 1:15. PI. 4. f. 210. 1837. 

 Helicosporium muelleri SAGO. Mich. 2:129. 1880. 

 Helicomyces veqetus (Nees.) 



Helicosporium vegetum Nees. Syst. 68. /. 09. 1816. 



36. HELICOMA Corda. Ic Fung. 1:15. 1837. 

 Vegetative hyphae creeping; sporophores short, ascending, 



sub-simple, hyaline or fuscous; conidia thick, rigid, elongate - 

 oblong or linear, closely and firmly uncinate convolute, hyaline 

 or fuscous, not hygroscopic. 



9 species are reported from this country. 



37. HEL1C00N Morg. N. Am. Helicosporae, 49. 1894. 

 Vegetative hyphae present or obsolete; sporophore short and 



erect or obsolescent, septate, hyaline or fuscous; conidia elon- 

 gate-filamentous, coiled into a conic-elliptical body, hyaline or 

 fuscous. 

 4 species reported. 



Tribe Diplosporieae. 

 Sporophores erect, rigid, more or less inflated at the joints, 

 branched; conidia acrogenous on the ends of the branchlets, 

 catenulate. 



38. DIPLOSPORIUM Lk. Sp. PI. 1:64. 1824. 



Ckidotrichum Corda. Sturm Deutschl. Fl. in. 3:39. 1837. 



Vegetative hyphae creeping; sporophores erect, black, some- 

 what rigid, more or less inflated at the joints, branched; con- 

 idia acrogenous, short catenulate, or apparently single, one- 

 septate, fuscous. 



3 species are reported from the United States. 



Tribe Sporodesniieae (Fu.) 



Sporodesmiei Fr. Summ. Veg. Scand. 2:505. 1849. 

 Vegetative hyphae obsolescent or obsolete; sporophores 

 erect, micronemeous, typically simple, much shorter than the 

 conidia or at most scarcely equalling them, often unicellular, 

 sometimes even entirely obsolete, usually forming more or less 

 distinct capitula, hyaline or fuscous; conidia single, i. e., never 

 catenulate, solitary, acrogenous, rarely acro-pleurogenous, 

 hyaline or fuscous, continuous or septate. 



