Leucopaxillus amarus: Leucopaxillus gentianeus
Cap 5-11 cm broad, convex, expanding to plano-convex, sometimes with a broad umbo; margin at first incurved, becoming decurved, obscurely to conspicuously striate; surface smooth, dry, dull, reddish-brown to cinnamon brown, the margin lighter; flesh thick, white; taste bitter, odor usually unpleasant.
Gills close, adnate to notched, sometimes slightly decurrent, narrow, white, becoming cream.
Stipe 4-8 cm tall, 1-2.5 cm thick, equal or tapering to an enlarged base; surface white, smooth, sometimes developing brownish stains at the base, the latter embedded in a layer of dense, white mycelium; veil absent.
Spores 4.5-6 x 3.5-5 µm, nearly round, warted, ornamentation amyloid; spore print white.
Forming rings and arcs under conifers, e.g. coast redwood, Monterey pine, and Monterey cypress; less common with hardwoods; fruiting from late fall to mid-winter.
Inedible; very bitter.
Leucopaxillus gentianeus is a medium sized, robust mushroom with a dull, reddish-brown to cinnamon-brown, striate cap. It resembles some of the red-brown Tricholomas, but none have the combined characters of a dense, white mycelium and a bitter taste. An examination of the spores, which are nearly round and have amyloid ornamentation, will also help confirm an identification.