The North American Species of Crepidotus

3. Crepidotus stratosus sp. nov.

Illustration: Fig. 36.

Pileus 8-15 mm latus, albus, siccus, fibrillosus, margine pubescens, involutus. Lamellae primum albae, cinnamomeae siccatae, confertae, latae, marginibus plus minusve fimbriatae. Sporae 7-12 x 4-6 µ, ovoideae demum ellipsoideae infronte, in imagine obliqua inaequilaterales, minimum punctatae, parietibus tenues. Basidia (20) 25-34 (41) x 6-8 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 35 -70 (104) x 3-8 µ. Pilei trama duplex: interior triens e densis intertextis hyphis compositus, pars exterior laxe intertexta, superficies gerens caespitem ex erectis hyphis compositus. Fibulae desunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Priest Lake, Idaho, Oct. 17, 1956, A. H. Smith 54909.

Pileus 8-15 mm broad, white, dry, resupinate, at times more or less laterally attached, fibrillose, margin inrolled, pubescent. Context white; odor and taste none. Lamellae radiating from a lateral point, white at first, drying cinnamon, close or crowded, broad, edges more or less fimbriate.

Spores 7-12 x 4-6 µ, ovoid to ellipsoid in face view, inequilateral in profile, minutely punctate, thin-walled, pale ochraceous tawny in KOH. Basidia (20) 25-34 (41) x 6-8 µ, 4-spored. Pleurocystidia none; cheilocystidia 35-70 (104) x 3-8 µ, filamentous, cylindric, subclavate, at times subventricose, often flexuous, more rarely forked, branched, or coiled. Gill trama somewhat interwoven, hyphae 4-10µbroad. Pileus trama duplex: the inner (lower) third of densely interwoven hyphae, the outer (upper) portion loosely interwoven, the surface bearing a turf (at times more or less a palisade) of colorless, erect hyphae, 2.5-4 (6) µ broad. Clamp connections none.

Habit, Habitat, and Distribution: On hardwood and coniferous wood and soil, Michigan, Idaho, and California, October and December.

Material Studied: CALIFORNIA: Smith 56900; IDAHO: Smith 53796, 53817, 53818, 54909 (type, from Priest Lake, Oct. 17, 1956), 55247, 55248, 55249; MICHIGAN: Smith 50783.

Observations: The duplex character of the pileus trama, the long cheilocystidia, and rather large spores distinguish this species. Two Idaho collections were on soil.