The North American Species of Pholiota
66. Pholiota silvatica (Smith) comb. nov.
Stropharia silvatica Smith, Contr. Univ. Mich. Herb. No. 5, p. 65, 1941.
Illustrations: Text figs. 164-167.
Pileus 2-4 cm broad, obtuse, margin incurved slightly at first, becoming plane or with an obtuse umbo, the margin at first decorated with veil fragments, glabrous otherwise, viscid to glutinous, evenly "amber brown" to "argus brown" in buttons, soon fading to "amber yellow" along the margin and in age only the disc or umbo amber brown, the remainder "chamois" (pale yellow), not translucent striate at any time. Context concolorous with the surface, watery, moderately thin and pliant, odor and taste mild.
Lamellae adnate with a tooth and readily seceding, ventricose and broad (5-6 mm), close, 27-30 reach the stipe, 2-3 tiers of lamellulae, white when young, becoming "deep olive buff" and finally "Saccardo's umber" (dark yellow-brown) in age, edges even.
Stipe 8-16 cm long, 3-5 mm thick, equal above a long (4-6 cm) pseudorhiza, solid or with a narrow tubule, viscid over the lower two-thirds and sordid honey-yellow, upper part whitish but becoming pale yellow, a thin white inner fibrillose veil present beneath the glutinous veil; annular zone apical, evanescent; below the annular zone often more or less concentrically zoned from the drying gluten.
Spore deposit on stipe apex dull tawny; spores 10-13 x 5.5-7.5 µ, oval to elliptic in face view, in profile subelliptic to obscurely inequilateral, smooth, slightly truncate from a distinct apical germ pore, rusty cinnamon as revived in KOH, greenish-yellow in H2O mounts fresh, pale tawny in Melzer's reagent, wall 0.25-0.4 µ thick (estimated).
Basidia 30-35 x 8-10 u, subclavate to cylindric, 4-spored, yellowish-hyaline in KOH and in Melzer's reagent. Pleurocystidia abundant, 34-42 x 10-12 µ, clavate to broadly fusoid-ventricose to clavate-mucronate, apex subacute to obtuse, often with a highly refractive content in KOH (content typically yellowish and in lower half of cell-not an isolated clearly defined mass as in true chrysocystidia), some filamentose pseudocystidia 30-40 x 7-11 µ also present and with ochraceous content as revived in KOH. Cheilocystidia abundant, 28-36 x 10-14 µ, clavate to somewhat fusoid-ventricose, apex usually rounded, some with refractive content as revived in KOH. Caulocystidia abundant, often in clusters, 30-60 x 9-18 µ, utriform to clavate, hyaline in KOH, walls thin, content homogeneous; stipe hyphae hyaline in KOH and thin-walled, smooth.
Gill trama parallel to somewhat interwoven, non-gelatinous hyphae with tawny to ochraceous walls in KOH, walls thin and smooth; subhymenium a narrow region becoming gelatinous in KOH or remaining indistinct. Pileus cutis a gelatinous layer, the hyphae tangled loosely as in a collapsed trichodermium, 4-5 µ diam., mostly tubular, walls yellowish in KOH and incrusted; hypodermial layer of floccose hyphae rich tawny in KOH and cells 6-12 µ or more wide. Context hyphae interwoven, thin-walled, smooth, yellowish in KOH, inamyloid. Clamp connections present.
Habit, Habitat, and Distribution: Solitary under cedar and hemlock (Thuja plicata and Tsuga heterophylla, near Kalalock, Olympic Peninsula, Washington, May 1939, Smith 13509, type studied.
Observations: This species is closely related to P. aberrans in pigmentation and stature but differs in having a pseudorhiza, in having ventricose gills, and in the presence of a distinct veil of two layers.