18 BULLETIN 175, U. S. DEPARTMENT OF AGRICULTURE. 



nous or hollow, with a cartilaginous bark, and differs in substance from 

 the cap. 



Mycena and Collybia both have cartilaginous stems, but in young 

 plants of Collybia the margin of the cap is inrolled, while in Mycena 

 it is straight and closely applied to the stem. 



Species of Collybia are to be found in woods on rotten stumps, on 

 decayed leaves, and on lawns. A strong alkaline or rancid odor is 

 peculiar to some species, and the presence of such a character should 

 be noted while collections are fresh. Many species are edible. 



Collybia butyracea. 



Cap reddish brown, dark in center, becoming pale toward the margin, convex, then 

 expanded, somewhat umbonate, smooth, even, dry but feeling oily; flesh soft, buttery, 

 whfte or flesh colored; gills thin, crowded, slightly adnexed, edge notched, white, 

 never spotted; stem cartilaginous, striate, hollow or stuffed, reddish, generally 

 smooth, but may be downy, attenuated upward. 



Cap 2 to 3 inches broad; stem 2 to 3 inches long. (PL XV, fig. 1; from Geological 

 and Natural History Survey of Connecticut.) 



Collybia butyracea may be distinguished from C. dryophila, by the variable color of 

 the dark, umbonate, greasy-looking cap, the somewhat uneven edges of the gills, and 

 the upward-tapering stem . It is found solitary or gregarious in woods, especially under 

 coniferous trees, and it is reported to be edible. 



Collybia dryophila. 



Cap convexo-plane, sometimes depressed in center, smooth, tan or reddish bay 

 brown, margin even or sometimes irregular, incurved when young; flesh white, thin; 

 gills narrow, crowded, almost free, or with a decurrent tooth, white or pale; stem 

 smooth, cartilaginous, hollow, yellowish or reddish, base sometimes enlarged. 



Cap 1 to 3 inches broad; stem 1 to 3 inches long, 2 to 4 lines thick. (PL XV, fig. 2.) 



The species is common, usually found in woods, but sometimes in lawns and open 

 places, and is subject to variations difficult to definitely describe. One peculiarity 

 occasionally observed is the development of certain abnormal outgrowths of the cap 

 tissue. 



Collybia dryophila is reported to be edible by American mycophagists, but one for- 

 eign authority has cited a case of illness which followed its use. 



Collybia platyphylla. Broad-gilled Collybia. (Edible.) 



Cap convex, then expanded plane, brown or grayish, streaked with dark fibrils, 

 watery when moist, margin upturned in wet weather or when old; flesh white; gills 

 broad, distant, deeply emarginate, white, soft, broken or cracked when old; stem 

 whitish, stuffed, striate, sometimes powdered at the apex, bluntly rooted. 



Cap 3 to 4 inches broad; stem 3 to 4 inches long, 6 lines thick. (PL XVI, figs. 1 

 and 2.) 



This quite common species is one of the large mushrooms found in the early spring 

 and continuously until autumn. In common with several species of this genus, it 

 presents numerous variations and abortive growths; hence, its identification is some- 

 times puzzling. The abundant, cordlike rooting mycelium may assist in its recogni- 

 tion. It grows either solitary or gregarious on ground containing decaying wood and 

 among leaves near old stumps. 



