164 NEW YORK STATE MUSEUM 



ish brown color common to the mature gills of all the species of this group. 

 The stem is long, furnished with a collar and terminates at the base in an 

 abrupt flattened bulb. This bulb is suggestive of the specific name and is 

 a very available character by which to separate this mushroom from closely 

 allied species. The stem is smooth or minutely flocculent or mealy, stuffed 

 or hollow, equal or slightly tapering upward and white. Its collar is gen- 

 erally large and flabby, softly flocculent or woolly on the lower surface, which 

 is yellowish, rather thick toward the margin and thinner toward the stem. 

 Sometimes it separates readily from the margin of the cap as the latter 

 expands, in which case it adheres to the stem as an entire but flabby collar. 

 In other cases it adheres more firmly to the margin of the cap and becomes 

 torn by its expansion, leaving a partial or lacerated collar on the stem and 

 ragged fragments attached to the margin. The woolly layer of the lower 

 surface sometimes separates in flakes of radiating patches, as in the field 

 mushroom. Because of this character and other points of resemblance 

 between the two species, this mushroom was considered a variety of the field 

 mushroom in report 48, p. 141, and named variety abruptus. In report 

 36, p. 47 it was confused with Agaric us silvicola, with which it agrees 

 very closely, but from which it may be separated by the flattened bulb of its 

 stem and the double character of its collar. The cap is 2 to 4 inches broad ; 

 the stem 3 to 5 inches long, 3 to 6 lines thick. 



Its flavor is considered inferior to that of the common mushroom, A. 

 campester, but it is worthy of acceptance as a fairly good mushroom. 



Agaricus silvicola Vitt. 



Forest Mushroom 



PLATE 59, fig. I- J 



Pileus convex or expanded, smooth or slightly silky, white, flesh white ; 

 lamellae thin, close, rounded behind, free, pinkish when young, becoming 

 darker with age, finally brown or blackish brown ; stem long, equal, smooth, 

 stuffed or hollow, bulbous, white ; spores elliptic, .0003 of an inch long, 

 .00016 broad. 



The forest mushroom has been regarded by some mycologists as a 

 variety of the common mushroom, from which it is easily distinguished by 



