The North American Species of Pholiota

153. Pholiota brunnescens sp. nov.

Illustrations: Text figs. 325-327; 447-450; pls. 40a, 71.

Pileus 2-7 cm latus, convexus demum late convexus vel obtuse umbonatus, glutinosus, squamulosus, glabrescens, sordide luteo-brunneus, subhygrophanus. Lamellae adnatae, angustae, confertae, albidae demum cinnamomeae. Stipes 4-6 (9) cm longus, (4) 8-10 mm crassus, aequalis, albidus demum pallide luteus, tactu brunneus, Iuteo-fibrilloso-cingulatus. Sporae 6-7 x 4-4.5 µ. Pleurocystidia 48-70 x 9-16 µ, fusoide ventricosa, saepe bifurcata. Caulocystidia 40-120 x 15-40 µ versiformia. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Lake Tahkenitch, Ore., Nov. 18, 1935, Smith 3525.

Pileus 2-7 cm broad, convex with an incurved margin, expanding to plane or retaining a low umbo, at times slightly depressed around the umbo, viscid to glutinous, at first sparsely decorated with small, whitish veil remnants forming evanescent fibrillose squamules, "Prout's-brown," "chestnut-brown," "tawny-olive," or "snuff-brown" (dark yellow-brown) margin at times fading to "apricot-orange." Context rather thick, dingy watery brown; odor and taste mild or slightly disagreeable.

Lamellae adnate to adnexed, at first whitish, becoming dull cinnamon, narrow, crowded, edges even or nearly so.

Stipe 4-6 (9) cm long, (4) 8-10 mm thick, equal, whitish to ivory-yellow, with numerous concentric fibrillose zones of citrine-yellow veil remnants, the surface staining tawny in age or where handled.

Spores 6-7 x 4-4.5 µ ovate to subelliptic in face view, obscurely inequilateral to elliptic in profile, smooth, wall slightly thickened (± 0.3 µ), apex with an extremely minute pore (1.4), pale to medium tawny in KOH, pale tawny to ochraceous in Melzer's reagent.

Basidia 18-22 x 5-6 µ, 4-spored, hyaline in KOH, yellowish in Melzer's reagent. Pleurocystidia 48-70 x 9-16 µ, abundant, fusoid-ventricose, apex obtuse, wall thin and hyaline, content homogeneous or with coagulated ochraceous content in neck as revived in KOH, in Melzer's reagent the coagulated material rather rusty-ochraceous to dingy orange-brown, many forked (with 2 necks). Cheilocystidia 32-47 x 9-14 µ, subfusoid to broadly fusoid or fusoid-ventricose, thin-walled, hyaline to ochraceous in KOH, smooth. Caulocystidia in tufts, voluminous 40-120 x 15-40 µ, thin-walled, smooth, content homogeneous, clavate to clavate-mucronate to fusoid, some forked, wall yellowish in KOH.

Gill trama of a floccose central area of parallel to subparallel smooth thin-walled hyphae with the cells 4-12 µ diam., subhymenium of gelatinous narrow (2-3 µ) closely packed hyphae. Pileus cutis a thick gelatinous layer of hyaline to yellowish smooth hyphae 1.5-3 µ diam., over this veil hyphae occur in places; the latter nongelatinous 3-6 µ and with yellowish incrusted walls; hypodermium of dark rusty brown hyphae from coarse incrustations, walls thin to slightly thickened, hyphae 5-10 µ diam. Context hyphae inflated 9-20 µ ±, walls thin, smooth, yellowish in KOH. All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: Gregarious to caespitose on burned areas in the Pacific Northwest, fall, common after forest fires.

Observations: This species is very distinct as it occurs in the Pacific Northwest by its voluminous caulocystidia which are for the most part quite unlike any of the lamellar cystidia. It is also a larger fungus than P. highlandensis and with rather conspicuous zones of yellow veil remnants on the stipe. However, the flecks of veil fibrils forming the squamules on the pileus are pallid. Another interesting feature is the number of pleurocystidia which are forked. The thick-walled cells in the hypodermium of the pileus are most numerous in sections of older material.

Material Examined: CALIFORNIA: Smith 3767, 9056, 9452. IDAHO: Smith 44678, 53782, 55283, 69248, 71307, 73889, 73890, 74092. OREGON: Smith 3411, 3462, 3525, (type), 3601, 3617, 3767, 55353.