The North American Species of Crepidotus

112. Crepidotus cinereipallens sp. nov.

Illustrations: Fig. 186.

Pileus 5-15 mm latus, sessilis, flabelliformis demum suborbicularis, pallido-aqueo-cinereus deinde pallidus, glabrosus. Lamellae cinereo-pallidae deinde "avellaneous," confertae, angustae demum medio-latae. Sporae 7-9 x 4.5-5.5 (6) µ, ellipsoideae, rugosae, "tawny olive" cumulatae. Basidia 20-28 x 6-7 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 22-40 x 4-15 (27) µ. Cuticula ex hyphis repentibus composita, hyphas erectas paucas gerens. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum in Cheboygan County, Mich., Oct. 9, 1955, A. H. Smith 50945.

Pileus 5-15 mm broad, sessile, flabelliform to nearly circular in outline, when moist pale watery gray, pallid when faded, glabrous, translucent striate, non-byssoid at the base. Context very thin and very soft; odor and taste mild.

Lamellae grayish-pallid becoming buffy avellaneous, close, narrow to medium broad, with more or less three tiers of lamellulae, edges even. Spores "tawny olive" in deposit. Spores 7-9 x 4.5-5.5 (6) µ, ellipsoid to ovoid in face view, slightly inequilateral in profile, wrinkled. Basidia 20-28 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 22-40 x 4-15 (27) µ, clavate, fusoid-ventricose, more rarely broadly napiform. Gill trama interwoven, hyphae 6-14 µ broad, cells at times inflated; hyphae of the subhymenium subparallel, narrow. Pileus trama interwoven, cells inflated especially toward the surface.. Cuticle of repent hyphae, only a few erect. Clamp connections present.

Habit, Habitat, and Distribution: On basswood bark, Michigan, October.

Material Studied: MICHIGAN: Smith 50945, type, from Mud Lake Bog, Cheboygan County, Oct. 9, 1955.

Observations: The distinctive features of C. cinereipallens include the grayish pileus and gills, the absence of epicuticular hyphae on the pileus, and the broad cheilocystidia.