656 MINNESOTA BOTANICAL STUDIES. 



Vegetative hyphae creeping or obsolete; sporophores erect 

 or ascending, elongated, typically much longer than the coni- 

 dia; simple or branched, scarcely acervulate, hyaline or fuscous; 

 conidia single, rarely catenulate. solitary, hyaline or fuscous, 

 acrogenous or pleurogenous. 



Most of the genera contain both saprogenous and phyllogen- 

 ous species. The genera are very hard to limit satisfactorily, 

 though well marked in typical forms, and many species need 

 to be transferred. The group is one of the most difficult among 

 the Imperfect Fungi. 



27. CLAD0SP0RIOI Lk. Obs. 2:37. 1813. 

 Sporophores erect or ascending, branched, elongated, fus- 

 cous; conidia single, sometimes catenulate, acrogenous or acro- 

 pleurogenous, oblong or ovoid to globose, fuscous, typically 

 one- septate, rarely 2-3-septate. 



Many of the species need further examination. About 50 

 are reported for the United States. 



28. HETEROSPORIIM Klotsch. Herb. Myc. 1: No. 27 



1832. 



Sporophores erect or ascending, sub- acervulate, simple or 

 ramulose, short, fuscous; conidia single, very rarely catenu- 

 late. acrogenous or acro-pleurogenous, oblong, echinulate or 

 verrucose, many- septate. 



Well distinguished by the echinulate or verrucose conidia. 



18 species are reported from the United States. Brachyspo- 

 rium sarraceniae MacMillan Bull. Torr. Bot. Club 18:214.1891, 

 having echinulate conidia, must be placed here. 



29. HELMINTHOSPORILMLk Obs. 110. 1809. 



Including Brachysporium Sacc. Mich. 2:28. 1880. 

 Vegetative hyphae obsolete; sporophores erect or ascending, 

 often branched, elongated, septate, fuscous; conidia single, 

 acrogenous or acro-pleurogenous, smooth, cylindrical to ovoid, 

 many- septate. 



As here limited, contains 70 species reported from this coun- 

 try. The following changes are required by our limitation of 

 the genus: 



Helminthosporium caxadense (E. & E.) 



Brachysporium canadensc E. & E. Jouru. Myc. 7: 134. 1892. 



Helminthosporium pedunculatum (Peck). 



Chisterosporium pedunculatum Peck. Rep. N. Y. Mus. 23:— (93). 1873. 

 Helminthosporium attenuation C. & P. Rep. N. Y. Mus. 29:-(50). 1S7S. 



Brachysporium gracile Sacc. Syl. Fung. 4:430. 1886, is the 

 same as Heterosporium gracile Sacc. Syl. Fung. 4:480. 1886. 



