Lilloa 22:154. 1951. 1949.
Common Name: none
Synonym: Hygrophorus flavifolius A.H. Sm. & Hesler
Cap 1.5-3.5 cm broad, obtuse-conic; becoming convex, eventually plane, translucent-striate to near the disc; margin incurved, then decurved to level, sometimes slightly upturned in age; surface glabrous, viscid-slimy, yellow, the disc fading to white, occasionally tinged lilac in youth; context white, unchanging, soft, up to 3 mm thick at the disc, thinning rapidly towards the margin; odor and taste mild.
Gills adnate to subdecurrent, fairly well-spaced, narrow, 1.5 -2.0 mm in width, apricot-orange in youth, fading to golden-yellow; edges even; lamellulae in two series.
Stipe 2-4 cm long, 4-6 mm in width, round, straight, cartilaginous, fragile, the core stuffed, equal to narrowed slightly at the base; surface slimy-viscid, translucent-white, glabrous except striate at the apex; partial veil absent.
Spores 7.0-9.0 x 4.0-5.5 µm, ellipsoid, smooth, thin-walled, hilar appendage conspicuous, contents of mature spores granular, inamyloid; spore print not seen, presumably white.
A beautiful but uncommon species, Hygrocybe flavifolia is recognized by small size, a slimy-viscid, striate yellow cap with a disc that fades to white, bright yellow gills, and a slimy white stipe. Occasional young specimens exhibit a lilac-tinged disc but soon fade to white. Hygrocybe flavifolia is distinctive but should be compared with Hygrocybe psitticina and Hygrocybe laeta. The former, commonly known as the "Parrot mushroom" has a slimy, striate greenish cap when young which fades to ochre, buff, pinkish, etc. but not yellow, while Hygrocybe laeta when young has a cap with lilac-grey tones that fades to pinkish-buff to tawny-olive. Neither has bright-yellow gills in age.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Hesler, L.R. & Smith, A.H. (1963). North American Species of Hygrophorus. University of Tennessee Press: Knoxville, TN. 416 p.
Largent, D.L. (1985). The Agaricales (Gilled Fungi) of California. 5. Hygrophoraceae. Mad River Press: Eureka, CA. 208 p.