Seaver: Hypocreales of North America 49 



Stroma very scant; perithecia 



subsuperficial. 28. Byssonectria. 



Stroma profuse ; perithecia im- 

 mersed. 29. Peckiella. 

 Spores i-septate, fusiform or subfusiform. 

 Stroma cottony or subfleshy ; spores 



fusiform. 30. Hvpomyces. 



Stroma fleshy; spores elliptical. 31- Hypocreopsis. 



Spores filiform. 



Perithecia enclosed in a membranaceous 



wall. 32. Oomyces. 



Perithecia not enclosed in a membrana- 

 ceous wall. 

 Stroma very scant, cottony, white. 33- Barya. 



Stroma subfleshy, of variable color. 

 Stroma sheathing, on stems of 



grasses. 34- Typhodium. 



Stroma patellate or subpatellate. 35. Hypocrella. 



Doubtful Genera 

 Glaziella. Fruit unknown. 



23. Hypocrea Fries, Syst. Orbis Veg. 104. 1825 



Stroma snbglobose to patellate, fleshy or subfleshy, usually with 

 an abrupt margin which in older specimens is more or less free, 

 or irregular in outline and effused without definite margin ; peri- 

 thecia entirely immersed, subglobose or ovate with the necks 

 slightly protruding ; asci cylindrical originally with 8 spores, each 

 of which separates into 2 subglobose or slightly cuboid cells, at 

 maturity i6-spored; spores subglobose or cuboid, hyaline. 



Type species : Sphaeria rufa Pers. 



Distinguished by the i6-spored asci and hyaline spores. There 

 is so little variation in the spores of the species of this genus that 

 we must depend almost entirely upon gross characters for diag- 

 noses of species. 



Stromata patellate, with definite outline, for the most 

 part on wood and bark. 

 Stromata dark colored, dark red, brown or purplish- 

 black. 

 Stromata red or brown. 



Stromata reddish-brown or dark brown. i. H.rufa. 

 Stromata wine-colored or dark red. 2. H. scutellaeformis. 



Stromata purplish-black or olive. 



Stromata purplish, large, .5-1 cm. in 



diameter. 3. H. lenta. 



