The North American Species of Pholiota

146. Pholiota fulvodisca sp. nov.

Illustrations: Text figs. 315-318.

Pileus 2-4 cm latus, demum late convexus, viscidulus saepe virgatus, ad centrum sordide argillaceus, ad marginem pallide subluteus. Contextus albus. Lamellae adnato-emarginatae, pallidae demum subcinnamomeae, latae, confertae. Stipes 2-4 cm longus, 7-12 mm crassus, aequalis, solidus, deorsum fulvus, sursum pallidus, deorsum fibrillosus vel subsquamulosus. Sporae 5.5-7 (7.5) x 3.5-4.5 µ leves. Pleurocystidia 50-72 x 8-16 µ, fusoide ventricosa. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope McCall, Idaho, 13 Aug. 1962. Smith 65898.

Pileus 2-4 cm broad, convex, expanding to plane or nearly so, disc clay-color to pale tawny, margin near "cartridge-buff" (pale yellow) slightly viscid but soon dry, more or less fibrillose streaked (virgate) with tawny fibrils and at first the margin fringed with remains of the whitish fibrillose veil. Context white, firm, thick; odor and taste not distinctive. FeSO4 instantly bright green.

Lamellae adnate becoming adnexed, pallid, finally becoming pale dingy cinnamon, broad, close, edges even.

Stipe 2-4 cm long, 7-12 mm thick, equal, solid to tubular, fleshy, dingy rusty brown in base, whitish above, surface whitish and silky above, brownish and fibrillose to subsquamulose below. Veil arachnoid, white.

Spores 5.5-7 (7.5) x 3.5-4.5 µ, smooth, apical pore minute; shape in face view ovate to elliptic, in profile obscurely inequilateral to subelliptic; color in KOH, rusty cinnamon becoming paler on standing, in Melzer's reagent soon dingy ochraceous, wall about 0.25 µ thick.

Basidia 20-26 x 5-6.5 µ, 4-spored, clavate, hyaline to yellowish in KOH and in Melzer's more yellowish. Pleurocystidia 50-72 x 8-16 µ, fusoid-ventricose to (rarely) rather narrowly ventricose, neck often flexuous, apex subacute to (rarely) capitate, wall thin or up to 0.5 µ thick, content ochraceous in KOH becoming paler on standing, often with rod-like particles in interior near apex. Cheilocystidia smaller than pleurocystidia and more often capitate (at times ninepin-shaped), usually ochraceous in KOH. Caulocystidia none.

Gill trama with a central floccose strand of hyaline to ochraceous or pale tan hyphae parallel and with thin smooth walls, cells short to elongated and 5-10 µ broad before inflation; subhymenium of hyaline gelatinous hyphae subparallel in arrangement, 3-5 µ diam., walls smooth. Pileus cutis a thin layer of hyphae imbedded in a gelatinous matrix, hyphae 3-5 µ diam., pale yellow to hyaline revived in KOH, wall smooth to asperulate; hypodermium of ochraceous to rusty floccose hyphae 4-10 µ diam., with encrusted walls. Content hyphae with cells inflated to 20 µ or more, walls thin smooth and weakly yellowish in KOH. All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: On conifer duff, near McCall, Idaho, Aug. 13, 1962, Smith 65898, type.

Observations: This species is close to P. spumosa but lacks caulocystidia, grew on duff, has a thinner pellicle covering the pileus, and pallid gills when young. It is closest to P. subfulva but the pleurocystidia have thinner walls, the FeSO4 reaction is bright green rather than dark olive, and its spores are a darker brown in KOH.