Name: Agaricus subrufescens
Citation: Ann. Rep. N.Y. St. Mus. 46: 25 (1894) 
Cap: 7-25 cm; round, sometimes shaped like a marshmallow when young, becoming convex to nearly flat; surface dry, when young covered with fine matted fibrils which break up into tiny scales, except at the center; fibrils pallid, buff, pale brown, or pinkish-brown; scales becoming darker brown or reddish with age; background color white to pinkish-buff; sometimes yellowing with age or when bruised.
Gills: Free from the stem; close; whitish when young, becoming pinkish, then reddish brown, and eventually dark chocolate brown.
Stem: 5-15 cm long; 1-4 cm thick; equal or enlarged at base; with a thick membranous partial veil which has cottony patches on the underside and which forms a high, skirt-like ring; white to pinkish above the ring; smooth or with fibrils or scales below; base often staining yellow with age or when bruised (but the flesh inside does not stain bright yellow when cut); base often with mycelial threads attached.
Flesh: Thick; firm; white; bruising very slightly yellow or not at all.
Odor and Taste: Like almonds.
Chemical Reactions: Cap yellow with KOH.
Spore Print: Dark brown.
Microscopic Features: Spores 5.5-7.5 × 4-5 µ; elliptical; smooth; inamyloid. Pleurocystidia absent; cheilocystidia 10-15 × 4-5 µ; abundant; inflated.