http://www.mushroomexpert.com/leucoagaricus_americanus.html Cap: 3-12 cm across; roundish when young, becoming convex and eventually broadly convex or nearly flat--but often featuring a shallow central hump; dry; bald in the button stage, but soon becoming scaly overall, with a bald center; at first whitish with tan to brownish red scales; becoming pinkish brown with deep reddish brown scales; reddening where handled. Gills: Free from the stem; close or crowded; short-gills frequent; creamy white when young; staining pinkish and eventually reddish brown. Stem: 4.5-12 cm long; 1-4 cm thick; distinctively swollen in the bottom half; bald or finely silky; firm; whitish at first, but soon discoloring reddish to reddish brown; bruising fairly promptly yellow, then slowly reddish, when rubbed; with a high, collarlike, collapsing ring that is initially white but becomes stained reddish; basal mycelium white; base attached to thin white cords. Flesh: White throughout; staining slowly yellow to orangish yellow when sliced; in age drying reddish; thick. Odor and Taste: Not distinctive.