This white (discoloring yellowish), thin-fleshed mushroom has a bell-shaped cap (which becomes flat when old) 1-3 inches wide, with a central knob, and radial grooves at the edge. It's covered with powdery white scales.

The crowded, free, narrow gills are white, with hairy edges, and the spore print is also white.

The slender stalk, which can be bulbous at the base, is 2-5 inches long, 1/8 to 1/4 inches thick. Covered with white, powdery scales, it bruises yellowish. There's a ring encircling the upper stalk.

Clusters of this species grow in wood chips, mulch, and compost throughout North America, from late spring to autumn.

This mushroom had been thought to be edible. After mushroom books reported that people had tried it with no ill effects, more people tried it, and some of them suffered very unpleasant gastrointestinal symptoms. Since then, more recent works list it as possibly toxic, and you should avoid eating it.