204 BRITISH FUNGI 



Pleurotus 



Cap excentric, sometimes resupinate, fleshy or very thin ; gills 

 decurrent or sometimes adnate, edge sharp and thin ; stem 

 gradually expanding into the flesh of the cap, excentric, lateral or 

 absent. 



The principal feature of the present genus is the excentric or 

 lateral stem. The species grow on wood, twigs, moss, etc., rarely 

 on the ground. Some are edible. 



ANALYSIS OF THE SPECIES 

 A. — EXCENTRICI 

 Cap entire, extended laterally, stem excentric but not truly 

 lateral. 



B. — Dl MIDI AT I 



Stem distinctly lateral, not marginate behind ; not resupinate 

 at first. 



C. — Resupinati 



Cap at first resupinate, then reflexed or turned o\'er, sessile ; 

 gills radiating from an excentric point. 



A. — Excentric: 



* Veil forming a ring on the stem. 



P. corticatus. — Cap convex, then expanded and almost plane, 

 horizontal, entire, everywhere covered with a dense greyish down 

 when young, which becomes broken up into squamules on a whitish 

 ground, edge strongly inturned when young, 4-8 in. across ; gills 

 strongly decurrent, forked, anastomosing behind, white, then 

 tinged yellow ; stem solid, hard, rooting, curved, squamulose, 

 white, ring cottony, thick, torn into shreds, 1-3 in. long. 



Often large and showy. The presence of a ring and the deeply 

 decurrent gills anastomosing behind are the points of the present 

 species. 



On trunks. 



P. dryinus. -~ Cap oblique or somewhat circular, compact and 

 hard, whitish, variegated with innate brownish scales, edge incurved 

 and bearing fragments of the torn veil, 2-4 in. across ; gills de- 

 current, very narrow, almost simple, not anastomosing, white, 

 tinged primrose ; stem very excentric, but not truly lateral, rarely 

 almost central, stout, about i in. long. 



The entire fungus becomes }^ellowisli when dry or bruised. 



On trunks of oak, hornbeam, etc. 



P. spongiosiis. — -Cap excentric, somewhat lateral, pulvinate, 

 covered with persistent grey down, 2-3 in. across ; gills sinuately 

 adnexed, with a decurrent tooth, simple, distinct, crowded, white, 

 edge entire ; stem up to i in. long, sometimes wanting, excentric, 



