Melanoleuca olesonii Murrill 1913

Melanoleuca olesonii Murrill, Mycologia 5: 218. 1913
Tricholoma Olesonii Murrill, Mycologia 5: 223. 1913.
Pileus convex to plane, large, rather thick at the center, fleshy, gregarious, reaching about 14 cm. broad; surface purewhite, smooth, glabrous, moist, margin thin, entire or slightly lobed, concolorous, not inflexed on drying; lamellae broad, ventricose, crowded, sinuate, white becoming discolored on drying ; spores ellipsoid, smooth, hyaline, 7-9 X 4r-5 x ; stipe short, thick, equal or slightly bulbous, smooth, glabrous, white, solid, about 4-5 cm. long and 2-3 cm. thick.
Type locality: Mission Cation, near Santa Barbara, California. Habitat: On the ground under an oak. Distribution: Known only from the type locality.