Cap 2-4 cm broad; brownish yellow to brownish orange, the disk darker and the margin paler; umbonate, becoming ± plane at maturity; distinctly radially fibrillose; oder spermatic; taste mild to slightly bitter or spermatic.
Gills yellowish, becoming darker from spores with age; with multiple series of lamellulae.
Stem yellowish, 3-7 mm broad x 45-70 mm long; equal or enlarged towards base which is typically sub-bulbous to bulbous; longitudinally striate and minutely hairy.
Spores 11.4 x 5.3-5.7 µm, smooth, brown in KOH.
Scattered, to gregarious under tanbark oak (Lithocarpus densiflorus) with Douglas fir (Pseudotsuga menziesii) nearby; January.
This distinctively colored Inocybe is known only from the type locality in San Mateo County.