The North American Species of Crepidotus

99. Crepidotus furcatus sp. nov.

Illustration: Fig. 170.

Pileus (4 )10-30 mm latus, sessilis, ungulatus demum applanatus, fibrillosus, glabrescens, albus deinde "pinkish buff" demum "cinnamon buff;" margine involutus. Lamellae albae, deinde "clay color" demum obscuro-ochraceae, confertae, angustae deinde ventricosae. Sporae 7-10 x 4.5-5.5 (6) µ, ellipsoideae demum ovoideae, punctatae. Basidia 28-35 x 6-8 µ, di- et tetraspora. Pleurocystidia desunt; cheilocystidia 30-50 x 4-10 µ, contorta velfurcata. Cuticula ex hyphis repentibus composita, hyphas erectas, sinuosas vel in spiram volutas gerens. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum in Cheboygan County, Mich., Oct. 9, 1955, A. H. Smith 50938.

Pileus (4) 10-30 mm broad,. sessile, ungulate to applanate, white, pubescent to villose, in age becoming more or less glabrescent and pinkish buff to cinnamon buff, margin inrolled. Context thin, white; odor and taste none.

Lamellae white becoming clay color to ocher tawny, close, narrow, becoming ventricose and medium broad, edges fimbriate.

Spores 7-10 x 4.5-5.5 (6) µ, ellipsoid to ovoid, obscurely inequilateral in profile, minutely punctate, yellowish-brown in 2% KOH. Basidia 28-35 x 6-8 µ, 2-4-spored. Pleurocystidia none; cheilocystidia 30-50 x 4-10 µ, cylindric, clavate, crooked, contorted, more rarely forked or knobbed. Gill trama interwoven, hyphae 5-8 (12) µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of colorless hyphae, 3-7 µ broad, the upper portions crooked or coiled. Clamp connections present.

Habit, Habitat, and Distribution: On hardwood, sticks and bark, Michigan, June-October.

Material Studied: MICHIGAN: Potter 3355, 3675 (MICH); Smith 50938 (type, on aspen, Mud Lake bog, Cheboygan County, Oct. 9, 1955), 50939,50940, 57088, 57886, 57888.

Observations: The moderately large spores and flexuous or contorted cheilocystidia, together with its crooked and coiled epicuticular hyphae, characterize this species.