North America - Illinois, Florida, Michigan, Minnesota, New York and west to Oregon and Washington.
Gregarious to scattered or solitary in pine, pine-hardwood areas or near Arctostaphylos. Fruiting September to Janurary.
Pileus 1.0-5.0 cm diam, convex to broadly convex and then nearly plane, not umbonate but at times shallowly depressed at center; margin incurved at first, later decurved, even, not rimulose; surface dry, sericeous-smooth to appressed-fibrillose towards the margin, violaceous fuscous then quickly mahogany red after application of KOH or NH40H (dried tissue conspicuously releases reddish pigment in 3% KOH); ochraceous tawny to ochraceous brown or olive brown, typically with grayish brown to fuscous tints over the disc; context very thin, whitish to pale yellow, unchanging when exposed, odor and taste not distinctive or like radishes. Lamellae adnate with decurrent tooth to sinuate, seceding in age; subdistant, with 3-4 tiers of lamellulae; narrow becoming ventricose; pale yellow to greenish yellow at first, becoming dull yellow and finally dull yellowish brown, drying rusty brown, edges pallid-fimbriate when young. Stipe 2.0-5.0 cm X 1.5-6 mm, equal or with slightly enlarged base; partial veil sparse, yellowish, evanescent; surface dry, fibrillose; pale yellow at first becoming dull ochraceous to dull ochraceous tawny; solid becoming hollow.
Basidiospores (9.0-) 9.5-10.9-12.5 (-13.0) X 3.0-3.6-4.0 (-4.5) μm; Q=(2.25-) 2.57-3.03-3.67 (n=50/3), smooth in alkali and Melzer's mounts, oblong-cylindric to subfusiform or boletoid, apices often obtuse; ± thin-walled; brownish yellow or yellowish brown like Inocybe spores, unreactive in Melzer's; apiculus small and indistinct. Basidia 26-35 (-40) X 6-8 μm, 4-sterimate, slenderly clavate, clavate, or cylindrico-clavate; hyaline but at times filled with ochraceous pigment or pigment granules in ammonia mounts, vinaceous in KOH. Pleurocystidia absent. Cheilocystidia absent but edges of lamellae may bear scattered sterile elements, these short, clavate, and thin-walled, 15-20 X 6-8 μm, mixed with basidia. Caulocystidia absent, terminal cells at times clavate or undifferentiated; stipe hyphae with conspicuous interhyphal pigment deposits, occasionally with incrusted appearance. Lamellar trama parallel, "Apricot Buff' or reddish yellow (7.5YR 6/8) in mass, hyphae cylindric to inflated, up to 15 μm diam; hyphae with scattered pockets of intense refractive ochraceous pigments, these at times appearing incrusted, becoming hyaline in KOH after diffusion of vinaceous pigments in solution. Clamps present.
