i6o 



MYCOLOGY 



or in the substratum, and are mostly spheric. A wall (peridium) is 

 present inclosing the clustered eight-spored asci which arise from the 

 interior basal part of the perithecium. The perithecium opens by an 

 apical mouth or pore and is either isolated or imbedded in a stroma 

 which takes manifold forms. The formation of conidiophores and 

 conidiospores varies in the different families and genera. Sometimes 



a distinct conidial layer is formed; at 

 other times the conidiospores are 

 formed in pycnidia. The suborder 

 includes many saprophytic and para- 

 sitic fungi found upon plants and 

 animals. 



Family i. Hypocreace^. — The 

 perithecium of these fungi is spheric 

 and opens terminally by a definite 

 pore. In color, it may be pale, 

 sprightly colored, or colorless, never 

 black. Hypomyces with sprightly 

 colored perithecia arises from a thick 

 crust-hke stroma. It lives parasitic- 

 ally on a number of different fleshy 

 fungi. For example, Hypomyces 

 lactifluorum transforms a species of 

 Lactarius into a cinnabarred growth 

 roughly resembling a toadstool and 

 without gills, while the original color 

 of the host is completely lost in the 

 higher color produced by the parasite. 

 Nectria without stroma has its peri- 

 thecia developed on the surface of the 

 substratum. N. cinnabarina is a par- 

 asite on various deciduous trees (Fig. 

 55). Its conidial form known as Tubercularia vulgaris produces flesh- 

 colored eruptions through the bark of various host plants. Nectria 

 ditissima grows on the beech. Polystigma has a crust-like stroma on 

 the leaves of trees of the genus Prunus, while Epichloe typhina con- 

 fines its parasitic attack to grasses upon which it develops orange- 

 yellow stroma. The genus Cordyceps consists of species which live 



Fig. 56. — Ergot {Claviccps pur- 

 purea) on rye head. {After Clinton, 

 G. P., Rep. Conn. Agric. Exper. Stat., 

 1903-) 



