PLEUROTUS. 363 



Sygrophorns Imdo-albus, Fries, Epicr., p. 324; Cke., Illustr., 

 pi. 915; Cke.,Hdbk., p. 293. 



In woods. 



Somewhat resembling H. ehurneus in habit and size, but 

 distinguished by the livid colour of the pileus and the gla- 

 brous stem. 



PLEUEOTUS. Fries, (figs. 12, 13, p. 301.) 



Pileus excentric, fleshy or membranaceous, sometimes re- 

 supinate ; gills usually decuirent, sonietimesi determinate 

 behind, or not running down the stem, rarely abruptly 

 adnate, margin acute ; stem expanding gradually into the 

 flesh of the pileus, excentric, truly lateral, or absent ; veil 

 present in some species ; spore more or less elliptical, 

 smooth. 



Pleurotus, Fries, Epicr., p. 129 ; Cke., Hdbk., p. 101. 



The principal feature of the genus is the excentric or 

 lateral stem. Most species grow on wooil, twigs, moss, &o., 

 rarely on the ground. In some of the higher species, P. cor- 

 ticatus, P. ulmarius, P. spodoleucus, &o., the stem is sometimes 

 central, and the pileus regular and horizontal. On the other 

 hand, certain species of Glitocyhe and Omphalia when growing 

 from an oblique or lateral substratum become excentric a^d 

 oblique. In Lactarius, Cantharenus, Marasmius, and the whole 

 of the other Leucosporae, there is nothing analogous with 

 Pleurotus. (Fries.) 



ANALYSIS OF TEE SPECIES. 



I. EXCESTRICI. 



Pileus entire, extended laterally, excentric but not truly 

 lateral. ' 



* Yeil forming a ring on the stem. 



-*» Yeil absent ; gills sinuate or obtusely adnate. 



*** Veil absent; gills deeply decurrent; stem distinct^ 

 more or less vertical. 



