The North American Species of Pholiota

194. Pholiota bigelowii sp. nov.

Pileus 3-4.5 cm latus, late convexus, sordide brunneus, in siccati laterarius; vellum sulphureum; lamellae sulphureae; stipes sursum sulphureus, deorsum sordide brunneus; spore 6-7.5 x 3.8-4.5 µ; pleurocystidia fusoide ventricosa vel subclavata, tenuitunicata; specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Mackinaw City, Mich. Aug. 27, 1953 (Smith 42423).

Pileus 3-4.5 cm broad, broadly convex with an incurved margin, expanding to plane or nearly so, color dull dark yellowish brown on disc ("Saccardo's umber") slightly paler to the sulphur yellow margin, in drying becoming evenly brick red, with flecks of veil tissue over marginal area at first, glabrous in age, slimy-viscid; veil yellow. Context thin and pliant yellowish, odor and taste not recorded.

Lamellae crowded, short-decurrent, narrow (caps all young) sulphur yellow, edges even.

Stipe 2-4 cm long, 3-6 mm thick, equal, hollow, collapsing in drying, surface sulphur yellow above, dingy yellow-brown below, veil leaving only an evanescent sulphur colored fibrillose zone.

Spores 6-7.5 x 3.8-4.5 µ, smooth with a minute apical pore, shape in face view ovate to subelliptic, in profile bean-shaped to obscurely inequilateral; color in KOH pale ochraceous to brownish ochraceous, in Melzer's about the same; wall about 0.25 µ or less thick.

Basidia 4-spored, 20-25 x 5-6.5 µ, pale sulphur in KOH from content. Pleurocystidia abundant, 46-68 x 11-16 µ fusoid-ventricose varying to clavate or elliptic-pedicellate, but projecting prominently, smooth, thin-walled, neck with yellow colloidal content in KOH, about the same color in Melzer's. Cheilocystidia similar to pleurocystidia but more subclavate to broadly ventricose with short neck and obtuse apex. Caulocystidia elongate-clavate, (36) 10-90 x 6-11 µ or near stipe-apex fusoid-ventricose and up to 90 x 14 µ, yellowish hyaline in KOH or with ochraceous coagulated content.

Gill trama a central strand of greenish ochraceous (in KOH) smooth, thin-walled hyphae in parallel arrangement; subhymenium of diverging narrow hyphae in a slime matrix. Pileus pellicle thick, of interwoven narrow gelatinous hyphae with disintegrating walls, yellow to hyaline in KOH, walls roughened as one approaches the hypodermium, reddish fulvous, of compactly arranged narrow (3-10 µ non-gelatinous hyphae. Context hyphae, greenish yellow in KOH, thin-walled, smooth, cells inflated to 15 µ ±. Clamp connections present.

Habit, Habitat, and Distribution: Gregarious on an old hardwood log, Mackinaw City, Hardwoods, Emmet County, Mich., Aug. 27, 1953. H. E. Bigelow, Smith 42423, type.

Observations: The species was thought to be an unusually bright colored collection of Pholiota spumosa when it was collected but the color change in drying and the variation in shape of the pleurocystidia make it amply distinct.