Var. al´bus Berk.—albus, white. A very common wild form. Cap 2–4 in. across, smooth or slightly fibrillose. Stem 1½-3 in. long, ⅓-⅔ in. thick, white or whitish. Spring to autumn, in rich grassy places. Sometimes very large. It is cultivated.
Var. gri´seus Pk.—griseus, gray. Cap grayish, silky, shining. Ring vanishing. Reported from Virginia.
Var. prati´cola Vitt.—pratum, a meadow; colo, to inhabit. Meadow variety. Cap covered with reddish scales. Flesh pinkish. Parade ground, Mt. Gretna, Pa.
Var. umbri´nus Vitt.—umber, dark brown. Cap brown, smooth. Stem short, minutely scaly.
“Var. rufes´cens Berk.—rufescens, becoming red. Pileus reddish, minutely scaly. Gills at first white. Stem elongated. Flesh turning bright red when cut or bruised. This departs so decidedly from the ordinary characters of the type, especially in the white color of the young gills, that it seems to merit separation as a distinct species.” Peck, 36th Rep.
Var. villa´ticus Brond.—belonging to a villa. Cap scaly. Stem scaly.
Var. horten´sis Cke.—growing in gardens. Cap brownish or yellowish-brown, covered with fibrils or minute hairs. This is a cultivated species.
“Var. Bu´channi. Cap white, smooth, depressed in center, the margin naked. Stem stout. Ring thin, lacerated. A rare variety, sometimes occurring in mushroom beds.
“Var. elonga´tus—elongated. Long-stemmed variety. Pileus small, smooth, convex, the margin adorned with the adherent remains of the lacerated veil. Stem long, slender, slightly thickened toward the base. Ring slight or evanescent. This is also a variety of mushroom beds.
“Var. vapora´rius. Green-house variety (A. vaporarius Vitt.) Pileus brownish, coated with long hairs or fibrils. Stem hairy-fibrillose, becoming transversely scaly. Conservatories, cellars, etc. Not differing greatly from Var. hortensis.” Peck, 36th Rep. N.Y. State Bot.