Leucopaxillus: spores white; gills white and separable from the pileus; stature: Clitocybioid. The genus is characterized by its warty to bumpy, amyloid spores.

In northern California, there are two species complexes of Leucopaxillus. Each species complex is easily recognized in the field. As the name implies, the white gills are separable from the pileus as in the brown-spored genus Paxillus.

1). Leucopaxillus amarus in the which the pileus is tan, the taste is bitter, and the copious white mycelium which binds the stipe base to the surrounding humus; thus when the stipe is pulled from the substrate, its base is accompained by the copious mycelium.

2). Leucopaxillus albissimus in the which the pileus and stipe are white with a yellowish trace and concolous and the Clitocyboid fruiting body is hard and solid. In this species, the abundant basal mycelium is often scant to absent.