The North American Species of Crepidotus

68. Crepidotus luteicolor sp. nov.

Illustrations: Figs. 19, 139, 140.

Pileus 2-4 cm latus, sessilis, flabelliformis, "picricyellow" demum "antimony yellow," anteriore glabrosus, posteriore albo-pubescens. Lamellae primum pallido- "picric yellow" demum "warm buff," deinde brunnaceae, confertae, angustae. Sporae 5-7 x 4-5.5 µ, ovoideae vel ellipsoideae, punctatae. Basidia 28-36 x 7-8 µ, di- et tetraspora. Pleurocystidia 28-42 x 8-10 µ; cheilocystidia 26-50 x 4-17 µ. Cuticula sine magno discrimine, superficies hyphas sine colore erectas et pileocystidia gerens. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Emerson, Mich., Aug. 12, 1963, Dick Homola, Smith -67119.

Pileus 2-4 cm broad, fan-shaped, the margin long remaining inrolled, surface "picric yellow" to "antimony yellow," outer half glabrous, basal half with a dense white-pubescent covering, moist and at maturity the extreme edge striatulate in one. Context whitish, firm-brittle; odor and taste mild.

Lamellae at first pale "picric yellow" to "warm buff," becoming near "Sudan brown," or dingy-orange-brown, close, narrow, attached at a basal point, often broken transversely.

Stipe none, caps broadly attached by a basal mycelial mat which is whitish and finally discolors to tawny.

Spores 5-7 x 4-5.5 µ, ovoid, more rarely ellipsoid, punctate. Basidia 28-36 x 7-8 µ, 2-4-spored. Pleurocystidia 28-42 x 8-10 µ, clavate, scattered; cheilocystidia 26-50 x 4-17 µ, mostly clavate, more or less capitate, with a tapering neck (more or less aciculate). Gill trama interwoven, hyphae 5-10 µ broad. Pileus trama loosely interwoven. Cuticle not distinctly differentiated, the surface bearing scattered or numerous, erect, colorless hyphae, the terminal elements scarcely cystidioid, hyphae 2.5-5 µ broad. Clamp connections present.

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

Material Studied: MICHIGAN: Smith 67119, type, from Emerson, collected by Dick Homola, Aug. 12, 1963.

Observations: The yellow pileus and gills and small, ovoid spores, together with pleurocystidia, distinguish it. Its colors, narrow gills, and pleurocystidia separate it from C. croceitinctus.