AAT ry 
It has been tested by Mr. G. Rodman. It is apparently a rare species, Aad 
- but may be more common than is supposed, for it may possibly have 
color on the disk. 
‘some species, often turning yellow when bruised.” 
46 THIRTY-SIXTH REPORT ON THE STATE. MUSEUM. 
The species is respectfully dedicated to its discoverer. Its edible | tf 
qualities are deemed equal to those of the common edible mushroom. 
been heretofore confused with the common mushroom, whichit much — 
resembles in color, the pileus being at first white or whitish, although 
it soon assumes yellowish tints or becomes a pale ochrey-red or russet 
AGARICUS ARVENSIS, Scheff. 
Horse Mushroom. Plowed-land Mushroom. 
Pileus at first convex or conical-campanulate, then expanded, at first 
more or less floccose or mealy, then smooth, white or yellowish, flesh - 
white ; lamelle close, free, generally broader anteriorly, at first whitish, 
then pinkish, finally blackish-brown ; stem equal or slightly thickened 
toward the base, smooth, hollow or stuffed with a floceose pith ; an-— 
nulus rather large, thick, the lower or exterior surface often cracked 
in a radiate manner; spores elliptical, .0003 to .0004 in. long, yl 
to .00025 in. broad. 
Plant 2 to 5 in. high ; pileus 3 to 5 in. or more broad; stem 4 to 
10 lines thick. 
Cultivated fields and pastures. Summer and autumn. 
‘This species is so closely related to the common mushroom that it 
is regarded by some authors as a mere variety of it. Kyen the re- 
nowned Persoon is said to have written concerning it, ‘‘ It appears to 
be only a variety of A. campestris.” Cordier says of it, ‘* Distinguished 
from A. campestris by its pure white color, more pale lamelle, its 
white flesh not changing color when cut or bruised, its lamelle re- 
maining pale a long time and not deliquescing.” Fries also says that ~ 
it is commonly not distinguished from A. campestris, but that it ig 
diverse in some respects; its white flesh being unchangeable, its la- 
mell never deliquescing, remaining a long time pale and not becom- 
ing dark red in middle age. Berkeley says of it, “ A coarse, but whole- — 
In size the horse mushroom often exceeds the common mushroom, 
its pileus, according to the Handbook, sometimes attaining a breadth ~ 
of eighteen inches and its stem a thickness of one to two inches, The 
white color of the pileus often becomes tinged with yellow, either with 
age or in drying. The pale primary color of the lamelle, the thick, 
well-developed annulus and the hollow stem are availible features for 
distinguishing it from its close allies, It is less common with us than 
A. campestris, to which in edible qualities it is very similar. A. 
Georgii, Sow., A. pratensis, Scop., A. edulis, Krombh., and A. ex- — 
quisitus, Vitt., are synonyms. i} 
