The North American Species of Pholiota

168. Pholiota subdefossa sp. nov.

Pileus 8-17 mm latus, late convexus, siccus, fibrillosus, albo-luteus; lamellae pallidae demum fulvae, latae, subdistantes, adnato-decurrentes; stipes 1-1.5 cm longus, 1-2 mm crassus, pallide luteus; sporae 9-11 x 5-6 µ, laetae fulvae (in KOH). Pleurocystidia 20-35 x 8-15 µ, subovata vel clavato-mucronata. Specimen typicum in Herb. Univ. of Mich. conservatum est; legit prope Sinclair, Maine, 17 Juli 1956, Bigelow 3331.

Pileus 8-17 mm broad, broadly convex with an incurved margin expanding to plane or nearly so, at times with a low broad umbo, surface dry and unpolished, matted fibrillose under a lens, margin opaque and even, color cream-buff varying to pale yellow on margin, colors slightly more intense on disc, hygrophanous and fading to whitish; context thin, whitish, no odor or taste.

Lamellae adnate with a short decurrent tooth, broad, close to subdistant, not forked or intervenose, arched, 2-3 mm broad, edges undulating and finely eroded.

Stipe 1-1.5 cm long, 1-2 mm thick, equal, curved, terete, central, hollow, fibrous, with a tuft of tomentum at base, surface fibrillose, apex with fine filaments from veil, when young, concolorous with pileus.

Spores 9-11 x 5-6 µ, smooth but tending to be obscurely angular, apical pore present but minute (apex not truncate); color in KOH rusty-fulvous, in Melzer's paler; shape in face view ovate to subelliptic; in profile obscurely inequilateral to suboblong; wall about 0.25-0.3 µ thick (thickest in KOH).

Basidia 4-spored, 20-26 x 8-9 µ clavate, mostly yellow in KOH. Pleurocystidia rare, 20-35 x 8-15 µ, ovate, clavate-submucronate to subelliptic, content homogeneous, yellow in KOH, wall thin and smooth, cheilocystidia similar to pleurocystidia but some seen with adhering debris. Caulocystidia versiform but mostly like the cheilocystidia.

Gill trama of ochraceous-walled hyphae with inflated cells; subhymenium of narrow branched non-gelatinous hyphae. Pileus cutis a loosely interwoven layer of non-gelatinous, hyaline to ochraceous hyphae 4-7 µ diam.; hypodermial region continuous with the pileus context, the hyphae inflated and with ochraceous walls fading to hyaline. Clamp connections present.

Habit, Habitat, and Distribution: Gregarious on wet humus beneath a conifer log, July 17, 1956, near Sinclair, Maine, Bigelow 3331.

Observations: The spores in KOH are the color of a Conocybe but are not truncate and the pileus lacks an hymeniform or cellular epicutis. The species might be placed in Galerina where it would go in section Porospora. The stature, however, is more like P. scamba than of any other species, and its essential characters place it in Pholiota or in Galerina.