The North American Species of Crepidotus

44. Crepidotus obfuscens sp. nov.

Illustration: Fig. 100.

Pileus 4-10 mm latus, sessilis, ungulatus, cinereus deinde pallido-flavidus denique brunnaceus, minimum pubescens. Lamellae pallidae, deinde brunnaceae, latae, paene confertae. Sporae 4-5.5 µ globosae, punctatae. Basidia 24-28 x 6-7 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 22-53 x 6-11 µ. Cuticula ex hyphis repentibus composita, pileocystidia sparsa gerentibus, 25-64 x 4-7 µ. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum in Colonial Point Hardwoods, Mich., Aug. 17, 1959, A. H. Smith 61427.

Pileus 4-10 mm broad, sessile, ungulate, at first gray, then pale yellowish, finally brownish, minutely pubescent, basal portion white-fibrillose, striate (dried). Context thin, pallid.

Lamellae pallid, then brownish, broad, nearly close, edges fimbriate. Spores 4-5.5 µ globose, punctate. Basidia 24-28 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 22-53 x 6-11 µ, more or less cylindric or ventricose, often enlarged at or near the base, at times somewhat strangulate. Gill trama subparallel, hyphae 4-8 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, with scattered pileocystidia , 25-64 x 4-7 µ cylindric, clavate, or ventricose; the pileus margin beset with numerous pileocystidia similar to the cheilocystidia. Clamp connections present.

Habit, Habitat, and Distribution: On hardwood logs, Michigan, August.

Material Studied: MICHIGAN: Smith 61427, type, from Colonial Point Hardwoods, Aug. 17, 1959.

Observation: The distinguishing characters of this species are its colors (color changes), its broad gills, and rather large cheilocystidia.