The North American Species of Crepidotus

109. Crepidotus submollis Murr., Mycologia 4: 245. 1912.

Illustrations: Figs. 27, 183.

Pileus 1-3 cm broad, sessile, conchate, dimidiate to subreniform, becoming applanate, white, dry, pruinose-pubescent to fibrillose, in age glabrescent and becoming somewhat cinnamon buff, margin sulcate or plicate, remaining inrolled for some time. Context thin, white; odor and taste none.

Lamellae radiating from the lateral point of attachment, white, becoming ferruginous, then clay color to ochraceous tawny, close, narrow, becoming ventricose and broad in age, edges even or crenulate.

Spores 7-9.5 x 4.5-5.5 µ, ellipsoid to slightly ovoid in face view, somewhat inequilateral in profile, minutely punctate. Basidia (22) 28-34 (39) x 6-8 µ, 4-spored. Pleurocystidia none; cheilocystidia 24-50 x 4-10 µ, crooked and contorted, ventricose, clavate, subcylindric, often forked or knobbed. Gill trama subparallel to slightly interwoven, hyphae 5-9 (15) µ broad. Pileus trama interwoven. Cuticle of repent hyphae, or not always sharply differentiated, the surface bearing a turf of colorless, straight hyphae, 3-6 µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On fallen twigs and limbs of hardwoods, Michigan, Washington, Oregon, and California, July, October-November, and February.

Material Studied: CALIFORNIA: Harper 27 (NY): MICHIGAN: Smith 36812, 49808, 50938, 63587, 66982; OREGON: Smith 19444; WASHINGTON: Murrill 572, type (NY), from Seattle, Oct. 20-Nov. 1, 1911, and 603.

Observations: The moderately large, obscurely punctate spores, the crooked or contorted cheilocystidia, and straight hyphae on the pileus are characteristic of C. submollis. The pileus margin apparently is not always sulcate-plicate.