The North American Species of Pholiota
113. Pholiota squarroso-adiposa Lange, Flora Danica 5: 101. 1940.
Pholiota intermedia Lange, Flora Agar. Danica 3: 55. 1938.
(non. P. intermedia Smith 1932 or P. intermedia Singer 1928)
Pileus 3-6 (8) cm broad, obtusely conic to convex, when young the margin incurved, becoming broadly conic to nearly plane but with a broad low umbo or more rarely merely convex, surface slimy viscid and at first covered with flat strap-shaped to triangular recurved scales 3-4 mm long on young caps and about 3 mm broad at base, in age the scales disappearing or becoming agglutinated and spot-like, young buttons dark rusty brown ("russet" to "Mars-brown"), becoming paler ("ochraceous tawny), and marginal area pale bright yellow ("antimony-yellow") and this color gradually becoming dominant as velar layer disappears. Context thick and pliant, yellow ("massicot-yellow") or pallid, often with a watery green line next to the gills, odor and taste not distinctive.
Lamellae pale yellow ("cream-buff") becoming more or less rusty from the spores, close, narrow (3-4 mm), adnate, equal in width, about 3 tiers of lamellulae, edges even.
Stipe 4-7 cm long, 8-10 mm thick, equal above an abrupt flanged or bulbous base, solid, becoming hollowed, pale yellow ("massicot yellow") within or fading to whitish, surface up to apical fibrillose zone covered with recurved straw yellow to ochraceous tawny scales which are floccose (perfectly dry); veil pale yellow fading to pallid, leaving an evanescent apical zone when it breaks.
Spore deposit near cinnamon-brown; spores 6-7.5 x 4.3-4.8 µ, smooth, apical pore present but inconspicuous; shape in face view broadly ellipsoid varying to subovate, in profile, subelliptic, cinnamon-brown in KOH and about the same in Melzer's reagent, wall about 0.25 µ thick.
Basidia 24-30 x 5.5-7 µ, 4-spored, clavate, yellowish to hyaline in KOH, yellowish in Melzer's reagent. Pleurocystidia abundant to scattered, 26-35 x 7-11 µ, clavate to oval-pedicellate, usually with a highly refractive inclusion which is hyaline to yellowish in Melzer's reagent, also present are scattered cells 33-48 x 9-13 µ with contracted wrinkled dark reddish-brown content in KOH and in Melzer's. Cheilocystidia 24-35 x 5-9 µ, clavate, fusoid, to fusoid-ventricose, apex obtuse; walls thin, yellowish to hyaline, smooth; content homogeneous and hyaline to yellowish, a few similar to the dark brown pleurocystidia also occurring. Caulocystidia versiform and size very variable; clavate, subcylindric, narrowly fusoid-ventricose, 25-55 x 6-9 µ; 20-40 x 5-6 µ; 30-65 x 7-11 µ or 26-35 x 6-10 µ; some elongate subellipsoid and up to 12-16 µ diam. with walls slightly incrusted.
Gill trama when properly revived of hyaline subparallel hyphae with elongate cells having smooth thin to slightly thickened hyaline walls (as revived in KOH); subhymenium a narrow gelatinous layer of compactly arranged narrow (2-5 µ ±) hyaline hyphae. Pileus cutis a thick gelatinous pellicle of narrow (1.5-4.5 µ) ochraceous to nearly hyaline hyphae (in KOH); over this occur the remains of scales composed of reddish tawny hyphae with short cells (1:w was 2:1 compared to 3-8:1), with smooth to roughened walls, the hyphae parallel in arrangement; hypodermial region of rusty cinnamon somewhat incrusted floccose hyphae 4-8 µ diam. Context hyphae interwoven, cells inflated, smooth-walled, walls thin to thickened slightly and showing as a pair of double lines. Clamp connections present. All hyphae inamyloid.
Habit, Habitat, and Distribution: Caespitose in large masses on alder and maple logs in the Pacific Northwest. Description from Smith 16892 Baker Lake, Wash., Sept. 12, 1941.
Observations: This material is the closest we have found in North America to Lange's P. squarroso-adiposa. It has the short rather broad spores, the yellowish young gills and the scaly cap and stipe exactly as Lange illustrates it. Also, in the cited collections the stipe usually dries darker at the base than at the apex.