Leucocoprinus lilacinogranulus

This is a key to gilled mushrooms, that is, mushrooms having a definite cap with a fertile surface consisting of gills. The fruiting body usually also has a stem, although that may be lateral or absent (usually, then, the mushroom is growing from wood). You can use this key to identify mushrooms that you find.

Fruiting body containing fibers (usually in the stalk)

Spore print "light-colored": white or buff, sometimes tinged with pink or tan. Greenish and (except for the Russulales) yellow spore prints also go here
Stalk fibrous, not fracturing like a piece of chalk

Gills free
Annulus usually present (on some small species, the partial veil may remain instead as scraps of tissue on the edge of the cap)
Cap often umbonate, often with a concentric design of scales that are an intrinsic part of the cap (not easily peeled off without taking part of the cap with it)
The cap is also usually egg-shaped or completely round (like a globe) at first - - it doesn't start to open until the stem is almost fully grown

Cap less than 3" across at maturity; usually less than 2
If flesh changes color when cut or bruised, it turns red, without any preliminary color
Cap scaly or powdery (or both!)
Stem typically tough, fibrous
Ring typically persistent, membranous

Cap or stem covered with powdery or shaggy flakes that brush off (and wash off!) easily, or
Cap or gills yellow
Cap margin typically striate, almost to the disk in maturity

Leucocoprinus lilacinogranulus     (P. C. Hennings) Locquin