Cap:15-35 mm diam., convex to subumbonate or subcampanulate, even but translucent-striate at the margin when moist, sometimes subrimose with age. glabrous with lobed to irregular margin, subviscid, dark brown to brownish-yellow, hygrophanous, context is pliant, whitish and thin in the pileus and staining blue when handled.

Gills:Adnate to subadnate, dark brown-violet with whitish edges.

Stem:50-80 x 1.5-2.5 (-4) mm. Equal, hollow, whitish to brownish or reddish and covered with small silky whitish fibrils. Veil thin fine silky fibrils on the stipe turning evanescent.

Spores:(5-) 6-6.5 (-7.7) x 4.9-6.5 (-7) x 3.3-4 microns. Rhomboid or subglobose in and subellipsoid in the side with a short basal appendage and with a narrow germ pore..

Sporeprint:Purple-brown violet in deposit.

Habitat:Solitary or in small groups on humus or muddy soil in deciduous forests of Liquidambar-Quercus at 500-1400 m elevation.

Distribution:Known only from the subtropical forests of Mexico.

Season:Fruiting in the summer months of June-August.

Dosage:Unknown.

Comment:Pileus, stipe and context staining green-blue to blackish when bruised. This species was named in honor of French mycologist Roger Heim, who along with Dr. Wasson contributed important studies concerning the sacred mushrooms of Mexico.