The North American Species of Crepidotus

33. Crepidotus brunnescens sp. nov.

Illustrations: Figs. 8, 86.

Pileus 8-15 mm latus, sessilis, fabelliformis demum conchatus, pallido-cineraceus, siccatus "Prout's brown,"fibrillosus. Lamellae confertae, latae vel medio-latae, nonnullae quidem lamellulae angustae. Sporae 4.5-6.5 µ, globosae demum ovoideae, punctatae. Basidia 18-24 x 4-6 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 30-51 x 5-8 µ. Cuticula ex hyphis repentibus composita, hyphas erectas et pilocystidia gerens, 30-68 x 2.5-6 µ. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Lewiston, Michigan, July 30, 1963, A. H. Smith 66957.

Pileus 8-15 mm broad, sessile, conchate to fan shaped, surface, hygrophanous and translucent, striate to near base, watery pallid moist, pallid  grayish faded (but usually dusted cinnamon from the spores), drying "Prout's brown," surface thinly fibrillose to fibrillose-pubescent, with a white strigose base. Context thin, fragile, taste none, odor none.

Lamellae close, broad to moderately broad, interspersed with narrow ones, attached to strigose base, edges even.

Spores 4.5-6.5 µ, globose to more or less ovoid, often obscurely angular, punctate, yellowish-brown in 2% KOH, wall thickened. Basidia 18-24 x 4-6 µ, 4-spored. Pleurocystidia none; cheilocystidia 30-51 x 5-8 µ, cylindric-constricted, clavate, often subcapitate, ventricose, or bottle-shaped. Gill trama slightly interwoven, usually undulating, hyphae 3-5 µ broad. Pileus trama interwoven. Cuticle of repent hyphae bearing scattered hyphae, and filamentous to clavate-subcapitate pileocystidia 30-68 x 2.5-6 µ. Clamp connections rare.

Habit, Habitat, and Distribution: On hardwood logs and stumps, Michigan,July.

Material Studied: MICHIGAN: Smith 66949 (type, on hardwood, from Lewiston,July 30, 1963) 66957, 66966.

Observations: This differs from C. hygrophanus in its more conchate pileus, the distinctive dark brown color when dried, and the presence of pileocystidia.