The North American Species of Pholiota

156. Pholiota paludosella (Atk.) comb. nov.

Naucoria paludosella Atkinson, Journ. Myc. 12: 193. 1906.

Illustrations: Text figs. 342-346; pls. 60b, 69a, 73.

Pileus (2) 3-5 (6) cm broad, obtuse to convex with an incurved margin, expanding to broadly convex to plane and at times with an obtuse umbo; ground color pale cream-color except for the tawny, scaly disc; surface more or less decorated with fibrillose squamules or patches from the remains of the buff-colored veil, eventually more or less glabrescent; margin fringed with veil remnants at first; viscid but soon dry. Content pliant, yellowish; odor mild or fragrant; taste not distinctive.

Lamellae sinuate, yellowish becoming cinnamon-brown and drying paler, close, narrow to moderately broad, pliant and gelatinous, edges even.

Stipe 3-6 (8) cm long, 3-4 (5) mm thick, apex pruinose and yellowish, becoming tawny to russet below, equal or nearly so, or bulbous, pliant, floccose-squamulose up to the annular fibrillose zone left by the broken veil, more or less glabrescent. Veil buff colored.

Spores 7-10 (12) x 4-5 (6) µ smooth, apical pore distinct and apex obscurely truncate, shape in face view mostly ovate varying toward elliptic, in profile somewhat inequilateral; dull ochraceous tawny to cinnamon in KOH, paler and more ochraceous in Melzer's reagent.

Basidia 20-26 x 5-7.5 µ, 4-spored (some 2-spored) clavate, yellowish in KOH, in Melzer's reagent duller yellowish. Pleurocystidia scattered, 36-52 x 9-12 µ, fusoid-ventricose, smooth, thin-walled, content often ochraceous and coagulated (as revived in KOH). Cheilocystidia 28-43 x 6-7 µ, versiform: fusoid-ventricose, subfusoid, to nearly clavate, thin-walled, smooth (or soon becoming so in KOH), content yellow to hyaline. Caulocystidia 38-66 x 4-8 µ and elongate, narrowly clavate ventricose, rostrate, subfusoid or 33-40 x 9-14 µ and utriform, mostly with yellowish walls in KOH, walls smooth and thin to slightly thickened.

Gill trama a somewhat interwoven strand of floccose hyphae 4-14 µ diam.; walls thin, yellowish in KOH and smooth; subhymenium a well developed layer of gelatinous narrow (1.5-3 µ wide) interwoven filaments giving rise at base of basidia to a palisade of septate hyphae each of which has a basidium as the terminal cell. Pileus cutis a thick layer of rusty brown hyphae 2.5-4 µ or more in diam. with incrusting bands and spirals of pigment, layer only subgelatinous in KOH, (space between hyphae slightly more refractive than normal for a non-gelatinous cutis); beneath this a hypodermial region of more enlarged (up to 12 µ) hyphae with thin yellow smooth walls. Context hyphae paler down to a ferruginous band (in KOH) of cells with somewhat thickened walls just above the subhymenium, the color intense in young caps. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: On hummocks, in sphagnum, Michigan, Ohio and Tennessee, September-October. Type studied.

Observations: The habitat, medium large spores, projecting pleurocystidia, and scaly, tawny pileus disc are distinctive features of this species. The yellow context at maturity, and yellow young gills and stipe-apex, separate it from P. sphagnicola. The anatomy of the apical pore of the spore is interesting in this species. There is a very slight inflation of the outer wall layer right around the pore which gives the apex a slightly different appearance than in other species of Pholiota. A second rather deceiving feature of the species is the almost pseudoparenchymatic band of cells with slightly thickened walls next to the subhymenium; in young material revived in KOH they are ferruginous red but in older caps almost colorless. This sort of pigment change has also been observed in Psathyrella species. In some older pilei areas of hymenium had apparently been destroyed by insects, and numerous pleurocystidia had replaced the basidia.

Material Examined: MICHIGAN: Harding 391, 409, 432; Smith 33-1014, 33-1041, 988, 4921, 50585, 62203, 64746; OHIO: 20076 (CU) TENNESSEE: Hesler 10930.