Figure 252.—Agaricus arvensis. Two-thirds natural size, showing veil.
Arvensis, pertaining to a field. Pileus is smooth, white or yellowish, convex or conical, bell-shaped, then expanded, more or less mealy. The gills are crowded, free, generally broader toward the stem; at first whitish, then pinkish, finally black-brown.
The stem is stout, equal, slightly thickened at the base, smooth, hollow or stuffed, ring rather large and thick, the upper part membranaceous and white, while the lower or exterior surface is thicker, downy, radically split and yellowish.
The spores are elliptical, .0003 to .0004 inch long.
This plant grows much larger than the common mushroom, and may be distinguished by the collar being composed of two parts closely allied to each other making a double membrane, the lower part being much thicker, softer in texture and split in a stellate manner into broad and yellow rays, as will be seen in Figure 252.
I found it very plentiful in Wood County, Ohio, and in quantities in Dr. Manville's yard in Bowling Green, Ohio. I ate them frequently and gave them to my friends, who all voted them delicious.
When the stem is first cut there exudes from the wound a yellowish liquid which is quite a sure ear mark of this species.
There is a tradition that the spores will not germinate unless they pass through the alimentary canal of the horse or some animal. However this may be, it is found frequently where no trace of the horse can be found. It appears from July to September. I have found it in Fayette County, Ohio, in large rings, resembling the Fairy-Ring Mushroom, only the ring is very large, as well as the mushrooms.