Leucopaxillus albissimus is a medium or at times large sized mushroom that is mycorrhizal with conifers or sometime eucalyptus. Some say it may be found decomposing the debris of conifers, but this is unconfirmed. The color of the cap or pileus of this mushroom varies and may be anywhere from white to buff, pinkish, pale brownish to pale tan.
The gills are pale yellowish to white in color are easily separated from the cap as a layer. The base of the stipe has a dense white mycelium.
West of the Rockies, particularly with a habit of conifer duff, the
species commonly considered L. albissimus, is more properly
Leucopaxillus paradoxus (Costantin & L.M.Dufour) Boursier (1925). In
the eastern US, the mushroom commonly considered L. albissimus is more
properly Leucopaxillus laterarius (Peck) Singer & Smith (1943). In
Europe, the mushroom known as L. albissimus is now synonymized with
Leucopaxillus cerealis (Lasch) Singer 1962
The basionym Agaricus albissimus Peck 1873 is a heterotypic synonym for Agaricus cerealis Lasch 1829. The latter species, indicated by the preferred name above is limited to Europe. Collections of “albissimus” from North America should be checked against Leucopaxillus paradoxus west of the Rocky Mountains on conifer duff, and Leucopaxillus laterarius east of the Rockies on hardwood duff.