The North American Species of Crepidotus

101. Crepidotus montanensis sp. nov.

Illustration: Fig. 173.

Pileus 5-15 mm latus, albus, villosus, senescens resupinatus, ungulatus, deinde flabelliformis. Lamellae albae deinde ochraceae, medio-latae, subdistantes. Sporae 8 -12 (12.5) x 5.5-7 µ, ellipsoideae vel subovoideae, rugosae vel subverrucosae. Basidia 26-32 x 7-8 µ, (di-)tetraspora. Pleurocystidia desunt; cheilocystidia 34-45 x 3-6 µ. Cuticula ex hyphis repentibus composita, hyphas erectas, sinuosas et in spiram volutas sine colore gerens, 3-6 µ vel 12-14 µ latas. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Echo Lake, Flathead National Forest, Mont., July 6, 1928, C. H. Kauffman.

Pileus 5-15 mm broad, white, villose, sessile, not resupinate at first but becoming so in age, ungulate then flabelliform, margin faintly plicate, base white strigose.

Lamellae medium broad, subdistant or nearly so, at first white then ochraceous, edges fimbriate.

Spores 8-12 (12.5) x 5.5-7 µ, ellipsoid, more rarely subovoid, slightly inequilateral in profile, wrinkled-rough to subverrucose. Basidia 26-32 x 7-8 µ, (2-) 4-spored. Pleurocystidia none; cheilocystidia 34-45 x 3-6 µ, filamentous, cylindric, clavate, ventricose, at times slightly constricted, more rarely capitate. Gill trama interwoven, hyphae 5-10 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of colorless, crooked and coiled hyphae, 3-6 µ broad, or at times some cells inflated and then 12-14 µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On mossy, living bark of birch, Montana, July.

Material Studied: MONTANA: Kauffman (MICH), type, from Echo Lake, Flathead National Forest, July 6, 1928.

Observations: The large wrinkled-subverrucose spores and the crooked and coiled hyphae on the pileus characterize it. It is closely related to C. epibryus, which has smaller spores. Kauffman, in his notes, designated it doubtfully as Crepidotus subversutus n. sp. But this binomial had been used by Peck for a fungus which is a Clitopilus, and was never validly published.