16 CIRCULAR 143, U. S. DEPARTMENT OF AGRICULTURE 
PLEUROTUS. 
The genus Pleurotus is chiefly distinguished among the white- 
spored agarics by the excentric stem or resupinate cap. The stem is 
fieshy and continuous with the substance of the cap, but it is subject 
to great variation in the different species and may be excentric, 
lateral, or entirely absent. The gills are decurrent or sometimes 
adnate, edge acute. Most of the species grow on wood, buried roots, 
decayed stumps. The genus corresponds to Claudopus of the 
Fictre 14.—Pleurotus ostreatus. (Edible) 
pink-spored and Crepidotus of the brown-spored forms. The best- 
known species of this genus is the oyster mushroom. 
PLEUROTUS OSTREATUS. OYSTER MUSHROOM, (EDIBLE) 
(Fig. 14) 
In the oyster mushroom the ¢ap is either sessile or stipitate, shell shaped or 
dimidiate. ascending, fleshy, soft, smooth, moist. in color white, cream, grayish 
to brownish ash: the stem is present or absent (if present. short, firm, elastic, 
ascending, base hairy): the gills are white, decurrent, somewhat distant, 
anastomosing behind to form an irregular network. 
The cap is 3 to 5 inches broad; mostly cespitose imbricated. 
This is a very fine edible species of cosmopolitan distribution growing on 
limbs or trunks of living or dead trees, and appearing from early summer until 
late fall. 
PLEUROTUS SAPIDUS. SAPID MUSHROOM. (EDIBLE) 
This species very closely resembles Plewrotus ostreatus but is distinguished 
from it by the lilac-tinged spores, a characteristic difficult or impossible for the 
amateur to detect. From the gastronomic point of view these two species are 
equally attractive. 
CANTHARELLUS 
In the genus Cantharellus the cap is fleshy or submembranaceous, 
continuous with the stem, the margin entire, wavy, or lobed. The 
gills are decurrent, thick, narrow, blunt and foldlike. regularly 
