The North American Species of Pholiota

59. Pholiota olivaceodisca sp. nov.

Illustrations: Text figs. 51-52.

Pileus 3-5 cm latus, convexus, viscidus, olivaceo-griseus, fibrillosus sparse squamulosus. Lamellae adnatae, pallide luteae, confertae, serrulatae. Stipes 4-6 cm longus, 5-10 mm crassus, luteo-fibrillosus, sursum albidus. Sporae in cumulo olivaceoluteae, 5.5-7 x 3.5-4 µ. Pleurocystidia desunt. Cheilocystidia 14-26 x 4-7 µ, fusoide ventricosa. Specimen typicum in Herb. Univ. Tenn. conservatum est; legit prope Claxton School, Anderson County, Tenn. 10 Nov. 1946. L. R. Hesler 17778.

Pileus 3-5 cm broad, convex, expanding, viscid, disc "deep olive-buff," elsewhere "olive-buff," fibrillose-appressed, with scattered spot-like scales, margin even. Context pale watery-white, medium thick; odor and taste mild.

Lamellae adnate to submarginate, "light buff" at maturity (yellowish), medium brown, rounded behind, crowded, edges serrulate. Stipe 4-6 cm long, 5-10 mm thick, near apex yellowish fibrillose, below white and floccose-scaly, tapering downward, tubular.

Spore deposit "Isabella color" (olive-yellow). Spores 5.5-7 x 3.5-4 µ, smooth, apical pore minute but distinct, apex obscurely truncate in some; shape ovate to narrowly elliptic in face view, in profile somewhat inequilateral; pale cinnamon brown in KOH, in Melzer's reagent paler and buff colored; wall about 0.25 µ thick.

Basidia 18-24 x 5-6 µ, 4-spored, short-clavate, hyaline in KOH, yellowish in Melzer's reagent. Pleurocystidia none. Cheilocystidia 14-26 x 4-7 µ mostly fusoid-ventricose to ventricose-rostrate with rounded apex, varying to subcylindric and slightly capitate, smooth, thin-walled, content homogeneous. Caulocystidia 18-40 (60) x 3-7 µ, cylindric to subcapitate or somewhat utriform, some filamentose with various enlargements and constrictions varying to narrowly clavate.

Gill trama a central area of floccose hyphae parallel to subparallel, the cells 5-12 µ or more wide (becoming inflated), walls thin, smooth, somewhat ochraceous to hyaline in KOH; subhymenium of narrow hyaline gelatinous hyphae ± interwoven to subparallel. Pileus cutis of loosely tangled subgelatinous hyphae 2-3.5 µ diam. with smooth walls and ochraceous content; hypodermial zone more rusty brown fading to ochraceous, walls smooth and not gelatinous. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Caespitose on soil, in mixed conifer-hardwood woods, Tennessee, November, Hesler 17778, type.

Observations: The pileus colors are unique. The disc is deep olivebuff, elsewhere it is paler (olive-buff). When dried the pileus assumes a dingy olive-ocher color. The color of the spore deposit, the small spores and small cheilocystidia and lack of pleurocystidia are a distinctive set of characters.