GILL FUNGI 



33 



Key to the Species 



(]ills beneath tlie cap or lateral 



a. Stem distinct, excentric ; gills adnexed or sinuate P. iilmarius 



b. Stem lateral or disappearing; gills decurrent 



(1) Cap horizontal or shelf-like 



(a) Spores white P. ostrcatus 



(b) Spores lilac-tinged against a white background /'. sapidus 



(2) Cap more or less erect and spatula-like l\ pctaloidcs 



2. Gills on the upper side, i. c., the cap reversed 



/'. applicatus 



Figure 20. Pleurotus ostreatus 



Pleurotus ulmarius Elm Cap 



Cap large, 8-15 cm. wide, while, whitish or tan, often brownish toward the 

 center, smooth, often cracked, usually convex, sometimes plane; stem long and 

 stout, often nearly central, 5-12 cm. by 2-3 cm., white or tan. smooth or hairy 

 toward the base, solid, elastic, often curved; gills adnexed or sinuate, whitish, 

 broad, close ; spores globose, 5-6|a. The name refers to its fondness for the elm. 



