[2] As of March 2023 there are over 200 accepted species of Leucoagaricus with ongoing research into the genus adding several more each year.

[3] Leucocoprinus is a similar genus and considered by some sources to be indistinct from Leucoagaricus based on genetic data that demonstrates they are monophyletic.

[4][5] As a result of the similarities and disagreement on taxonomy, many of the species within these genera have formerly been classified in the other and may still be known by previous classifications.

[6] This group of mushrooms was first defined as a subgenus of Leucocoprinus by Marcel Locquin in 1945, and it was then elevated to the status of genus by Rolf Singer in the journal Sydowia in 1948.

The group was characterized as belonging to family Agaricaceae with white, dirty cream or pink spores which are generally small (up to 10 μm) but much bigger in one species, with a germ pore, with a pseudo-amyloid multilayered membrane, simple or ornamented, which is metachromatic in cresyl blue.