rLKLUOTUS. 363 



HijgropJiorus Itvido-albus, Fries, Epicr., p. 324; Ckc, Illustr., 

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



In woods. 



Somewhat resembling; IT. i'hiirneus in habit and size, but 

 distinguished by tlie 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, sometimes determinate 

 behind, or not running down the stem, rarely abruptly 

 adnate, margin acute ; stem exi^anding 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., Ildbk., p. 101. 



The principal feature of the genus is the excentric or 

 lateral stem. Most species grow on wood, twigs, moss, &c., 

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

 ticatiis, P. idmarius, P. spodoleacus, &c., the stem is sometimes 

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

 hand, certain species of Clitocj/he and Omplialia when growing 

 from an oblique or lateral substratum become excentric and 

 oblique. In Laclarius, Cantharenus, Marasmiiis, and the whole 

 of the other Leucosporae, there is nothing analogous with 

 Pleurotus. (Fries.) 



ANALYSIS OF THE SPECIES 



I. EXCENTRICI. 



Pileus entire, extended laterally, excentric but not truly 

 lateral. 



* Yeil forming a ring on the stem. 



** Veil absent ; gills sinuate or obtusely adnate. 



*** Yeil absent ; gills deeply decurrent ; stem distinct, 

 more or less vertical. 



