The North American Species of Pholiota

71. Pholiota olympiana (Smith) comb. nov.

Hypholoma olympianum Smith, Mycologia 36: 248. 1944.
Naematoloma olympianum (Smith) Smith, Mycologia 38: 502. 1946.

Illustrations: Text figs. 94-95.

Pileus 2.5-4 (6) cm broad, obtuse to convex and with an incurved margin at first, expanding to plane or retaining a slight obtuse umbo, surface at first canescent from a thin coating of whitish silky fibrils but soon glabrescent or fibrils more or less persistent toward the margin, moist, color pale tan to clay-color ("cinnamon-buff" to "clay-color") on disc and paler and yellower on margin (dingy honey-color). Context hard and thick in disc when fresh, abruptly thinner toward the margin, pallid but soon lutescent where cut or broken, odor not distinctive, taste quickly and decidedly bitter.

Lamellae close, about 33 reach the stipe, 3-4 tiers of lamellulae, narrow (3-4.5 mm), bluntly adnate but seceding, "cream-buff" (very pale yellow) young, dull yellow-brown in age ("buckthorn-brown") and often with dark rusty spots, edges even and pale yellowish.

Stipe 5-7 cm long, 3-6 mm thick, subfusoid to equal above a long tapered pseudorhiza, tubular to hollow, surface densely white-fibrillose from veil remnants, apex yellowish and pruinose, becoming yellowish where handled and finally dark sordid brown, in age more or less glabrescent.

Spore deposit cinnamon-brown; spores 6-7.5 (9) x 4-4.5 (5.5) µ, smooth, apex rounded and lacking a pore; shape in face view elliptic to ovate, in profile about the same; color dull yellow brown revived in KOH, in Melzer's reagent pale tawny; wall thin (about 0.25 µ). Basidia 4-spored, 18-22 x 5-6 µ, projecting somewhat when sporulating. Pleurocystidia 22-36 x 9-15 µ, abundant, fusoid-ventricose to clavate-mucronate, with an irregular amorphous mass in the midportion as revived in KOH (hence they are chrysocystidia). Cheilocystidia 18-28 x 4-8 µ, narrowly clavate to subventricose, the apex rounded to obtuse, often yellow revived in KOH. Caulocystidia 18-28 x 4-10 µ, narrowly clavate to fusoid-ventricose, content homogeneous.

Gill trama of nongelatinous subparallel hyphae with yellowish to pale tawny walls in KOH; subhymenium of hyaline narrow hyphae not gelatinous. Pileus with an epicutis of narrow (1.5-2.5 µ), hyaline, non-gelatinous (to slightly gelatinous as revived in KOH) hyphae, smooth or practically so; hypodermium of brown-walled hyphae 5-12 µ diam., and more highly colored than the hyphae of the context. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Gregarious to scattered around Douglas fir stumps, Olympic National Park, Washington, Smith 18003, type.

Observations: This species is most closely related to Naematoloma radicosum from which it differs in the color of the spore deposit, and since the latter is yellow-brown the species is logically classified here. It is possible that some descriptions of the old Flammula amara apply to this species. Although the gills when mature in N. radicosum are dull rusty brown, the color of the spores in deposit is in the purple-brown spectrum.