Cap: 3-10 cm; broadly convex with an inrolled margin when young; becoming shallowly depressed or vase-shaped with an uplifted margin; slimy when wet; smooth or finely roughened; whitish to pale yellowish; typically with vague zones of color or texture, at least when young.
Gills: Beginning to run down the stem; close or crowded; pale yellowish; typically bruising tan.
Stem: 3-8 cm long; 1-2 cm thick; tapering to base; slimy when fresh or wet; usually with yellowish potholes by maturity; whitish.
Flesh: White; firm; appearing to yellow when sliced, due to the milk.
Milk: White, becoming yellow on exposure to air (usually quickly, but originally described by Burlingham (1942) as taking from 10 minutes to an hour to change color; staining white paper yellow.
Odor and Taste: Odor not distinctive; taste acrid (sometimes developing slowly).
Spore Print: Yellowish.
Chemical Reactions: KOH greenish yellow on cap surface.
Spores 6.5-9 × 6-7.5 µ; broadly ellipsoid or occasionally subglobose; ornamentation 0.5-1 µ high, as amyloid warts and connecting lines that branch into short patterns but do not form complete reticula. Pleuromacrocystidia scattered; subcylindric to subfusiform; to about 55 × 8 µ. Cheilocystidia abundant; subcylindric to fusiform; to about 50 µ long. Pileipellis a very thick ixocutis.