Eeport of the State Botanist. 47 



Agaricus silvigola, vat. 



Silvan Mushroom. 



Pileus convex or subcarapanulate, sometimes expanded or nearly 

 plane, smooth, shilling, white or yellowish ; lamellae close, thin, free, 

 rounded behind, generally narrowed toward each end, al first whitish, 

 then pinkish, finally blackish-brown ; stern long, cylindrical, stuffed or 

 hollow, white, hidhous ; annulus either thick or thin, entire or lac- 

 erated ; spores elliptical, .00025 to .00032 in. long, .00016 to .0002 in. 

 broad. 



Plant 4 to 6 in, high; pileus 3 to 6 in. broad; stem 4 to 8 lines 

 thick. 



Woods, copses and groves or along their borders. Summer and 

 autumn. 



Many authors place this as a variety of A. campestris, bat as it 

 occurs witli us its characters are very constant and well marked and 

 enable it to be distinguished from that species with great facility. It 

 generally attains a larger size, has a smoother, more shining pileus, 

 which is usually tinged with yellow, it has the primary color of the 

 lamellas whitish, and its stem is longer and proportionately more 

 slender and distinctly bulbous. It has, as Fries suggests, more points 

 of resemblance to A. arvensis than to A. campestris, but its bulbous 

 stem at once separates it from that species. The bulb is peculiar, it 

 being small but very abrupt and depressed or flattened like a common 

 turnip. The pileus is thin in proportion to its breadth and is quite fragile, 

 so that the plants must be handled with care to prevent its being 

 broken. In mature plants the margin of the pileus sometimes has a 

 lurid or dull purplish tint, which is probably derived from the color 

 of the spores. 



The annulus is often tinged with yellow exteriorly and is sometimes 

 radiately rimose on the lower surface like that of A. arvensis. In 

 some instances fragments of it remain attached to the margin of the 

 pileus. The plants sometimes grow in close groups or tuft-like clus- 

 ters. A. edulis, Berk., is given as a synonym. 



It is reported to be esculent, but I have not tested it. Persons un- 

 acquainted with it should guard against confounding immature speci- 

 mens of it with the white forms of the phalloid agaric, A. phalloides, 

 a poisonous .species which grows in similar places and bears some 

 resemblance to it. The poisonous A. phalloides has a much larger 

 bulb to the stem and the lamellae remain permanently white or whitish, 

 showing at no age either the pinkish or blackish-brown hues which 

 are so conspicuous in A. silvicola. 



