22 
Colorado Experiment Station 
appears usually during the latter part of summer and early autumn 
and should be known to every lover of mushrooms. 
Oyster Mushroom (Pleurotus sapidus )— Edible. 
Cap —Two to six inches broad, shell-shaped, often quite irreg¬ 
ular, smooth, smoky or wood brown in color. When young moist 
and rather tough. 
Gills —Not crowded, extending down onto the short stem, 
white. 
Spores —White on black background, pale grayish or lavender 
on white background. 
Stem —Very short or sometimes wanting, attached to one edge 
of the cap. 
Grows in crowded masses or clusters, often of many individ¬ 
uals upon decaying stumps or logs of cottonwood, poplar and simi¬ 
lar wood. This fungus can often be found year after year in the 
No. 17. The oyster mushroom (Pleurotus sapidus). Edible. A 
large cluster growing upon the trunk of a dead cottonwood. 
same places and occurs almost throughout the season when the 
moisture conditions are favorable. The caps should be used while 
comparatively young as they become tough with age and are also 
apt to be infested by insect larvae if left for some time. 
