The North American Species of Pholiota
181. Pholiota fibrillosipes (Murr.) comb. nov.
Gymnopilus fibrillosipes Murrill, North Amer. Flora 10: 199. 1917.
Pileus 2-6 cm broad, viscid, convex to conic or campanulate, then umbonate, at first "Kaiser-brown," then "tawny," or "cinnamon-rufous," "mars-orange" to "Sanford's-brown," disc "burnt-sienna" (bright ferruginous to orange-ferruginous) viscid, margin even, incurved and appendiculate, glabrous except for evanescent veil-remnants. Context "light ochraceous-salmon" to pale yellow, moderately thick in the disc, but thin on margin; odor and taste mild.
Lamellae adnate to adnexed or emarginate, "straw-yellow" to "Naples-yellow," finally "snuff-brown," broad, ventricose, close, or crowded, edges at first fimbriate, finally even.
Stipe 4-8 cm long, 2-8 mm thick, apex pallid or yellow, dark or dingy olive below, fibrillose, moist, stuffed, then hollow, often compressed, narrowed below. Veil copious, webby, pale yellow with some fibrils "Mars-orange," appendiculate, leaving a fugaceous apical ring.
Spores 6.5-8.5 x 4-4.5 µ, smooth, apical pore not distinct; shape in face view elliptic, in profile elliptic to very obscurely inequilateral; color in KOH ochraceous tawny, in Melzer's reagent paler and slightly yellower; wall thin (-0.25 µ).
Basidia 4-spored 20-25 (27) x 5.5-7 µ clavate, yellowish in KOH and in Melzer's reagent. Pleurocystidia 45-88 x 9-15 µ, fusoid-ventricose, apex obtuse, neck often plugged with ochraceous material (as revived in KOH); wall thin, smooth, hyaline to yellowish. Cheilocystidia 31-60 x 5-13 µ, subfusoid to fusoid-ventricose, smaller than pleurocystidia for the most part. Caulocystidia 36-54 x 8-12 µ, scattered, clavate to fusoid ventricose, walls hyaline to yellowish in KOH but not appreciably thickened.
Gill trama a central area of subparallel floccose hyphae 5-9 µ or more broad, yellowish to orange-brown as revived in KOH; subhymenium a thin layer of narrow gelatinous hyphae. Pileus cuticle a thick gelatinous pellicle of narrow (-3 µ) appressed-interwoven hyphae hyaline to yellowish in KOH; hypodermial region of orange-brown incrusted hyphae, the hyphal cells variable in size. Context hyphae yellowish to hyaline in KOH, interwoven. Clamp connections present. All hyphae inamyloid.
Habit, Habitat, and Distribution: Caespitose on soil, humus or sawdust, Tennessee, Alabama and Montana—summer and fall.
Observations: This species structurally is related to P. subcarbonaria but differs as shown in our key. Its individual features are the ferruginous colors (typical of the stirps) combined with spores ochraceous tawny under the microscope in KOH, bright yellow gills and copious colored veil.
In the Montana collection Cotner 570060 (MICH) the pileus was light vinaceous buff with the disc "cinnamon-rufous" and so is assigned here provisionally. There is not enough material of P. fibrillosipes known to indicate its pattern of color variation.
Material Examined: ALABAMA: Murrill, (type); MONTANA: Cotner 570060 (MICH); TENNESSEE: Hesler 14106, 20755 (TENN).