Cap 2.0-5.0 cm broad, narrowly conic, broadly conic to campanulate in age; margin incurved, then decurved, striate up to 1/4 the distance to the disc; surface viscid when moist, glabrous, occasionally appressed-fibrillose when dry; color red-orange to orange at the disc, yellow at the margin, in age greyish-yellow overall, or developing blackish areas, sometimes entirely black; context thin, watery, dull yellow-orange; odor and taste mild.
Gills notched, narrowly attached, often appearing free, close when young, subdistant in age, relatively broad, up to 1.0 cm wide, cream-yellow, eventually dull yellowish-grey, blackening slowly when injured or with age, greyish-black in old specimens; lamellulae up to four-seried.
Stipe 4.0-14.0 cm long, 0.5-1.0 cm thick, straight, equal, cartilaginous, hollow at maturity; surface viscid, appressed-twisted-striate, lemon-yellow or yellow, tinged orange, whitish at the base; blackening erratically with age and weathering; partial veil absent.
Spores 9.5-11.5 x 5.0-6.5 µm, bean-shaped in side-view, oblong-ellipsoid in face-view, smooth, thin-walled, hilar appendage inconspicuous; spore print white.
Scattered to gregarious in conifer woods; fruiting from mid to late winter; common.
Hygrocybe singeri is part of a group of viscid, waxy caps, interesting because of their tendency to blacken when bruised or with age. Traditionally these mushrooms were lumped locally under the name Hygrophorus conicus. We have followed the modern trend which recognizes several species in the group and places them in the genus Hygrocybe. Ironically, Hygrocybe conica, the best known of the species, may not be the most common member of the group in Northwestern California. It is recognized by a viscid, red/orange conic-cap with a moist, but not viscid stipe, and tendency for all parts to blacken. Hygrocybe acutoconica is similar but only the stipe base blackens. Hygrocybe singeri is distinguished by a viscid stipe, while Hygrocybe olivaceoniger is distinguished by a yellowish-green to olive, not red-orange colored fruiting body. Finally, Hygrocybe nigrescens, is separated from Hygrocybe conica by its slightly larger size, redder, more rounded umbonate cap, and association with oaks.