Pileus (Cap): 5-15mm in diameter. conic to subumbionate, papillate, glabrous, even but slightly straite at the margin by translucence when moist, subviscid to lubricous, hygrophanous, reddish brown to darker on the margin, finally blackish brown; readily staining blue when touched.
Lamellae (Gills): pale dark violet brown, sometimes with whitish subfloccose edges.
Stipe (Stem): 80-95 x 1-2mm, equal or slightly thickened at the base, hollow, hypogeous almost one half of the total length, reddish brown above to blackish toward the base; covered with white scales mainly in the middle portion.
Microscopic features: Spores 5-6.6x4.4-5.5 um rhomboid in face view, subellipsoid in side veiw, thick walled, dark yellowish brown, with a broad germ pore. Basidia 15-25 x 9-12um 4 spored, hyaline, ventricose to subpyriform. Pleurocystidia 16-30 x 6.6-13um scarce brownish or reddish yellow, rarely are hyaline, variable in form, fusiform or ventricose, often with a mucro, or with a short neck, or their are sublageniform.
Season: Fruiting in summer.
Habitat and Distribution: Growing on soil or humus, in deciduous forests or subtropical forests, with liquidambar styraciflua at 1500-1700m elevation. Known only from Mexico.