Pileo convexo-depresso, 6–10 cm. lato, glabro, albo, disco cremeo, sapore piperato; sporis globosis vel subglobosis, cremeo-albis, 6–8 µ longis; stipite albo, glabro, 4 × 1.5–2 cm.
Pileus convex to plane or somewhat depressed, not umbonate, gregarious, 6–10 cm. broad; surface smooth, glabrous, slightly viscid when moist, white with cremeous center, entirely cremeous in age or on drying, pellicle not separable, margin entire, rarely striate; context firm, white, odorless, soon rather acrid; lamellae rather narrow, crowded, equal, adnexed, entire, milk-white, becoming dingy yellowish-white with age; spores globose or subglobose, closely and conspicuously echinulate, creamy white, 6–8µ long; stipe tapering upward or sometimes equal, short, smooth, glabrous, milk-white, 4 × 1.5–2 cm.
Type collected by W. A. Murrill on a lawn under laurel oaks in Gainesville, June 4, 1938 (No. F 16403). Abundant under evergreen oaks in Gainesville early in June, 1938, and collected several times by the author. Its color and acrid taste at first suggested R. albidula, which grows commonly under pines and cedars, but it differs in shape, spore characters, habitat, taste, the color of the disk, and the adnate pellicle. Sterile cells are abundant on the edges of the gills, projecting about 30µ.
Holotypus: 16403 (F)
Published type studies: Hesler (1960).
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