The North American Species of Crepidotus

121. Crepidotus mucidifolius sp. nov.

Illustrations: Figs. 197, 198.

Pileus 6-12 mm latus, flavus, albo-tomentosus, primum cupulatus deinde applanatus, margine incurvatus. Lamellae albae deinde flavae, denique brunneaceae, angustae demum medio-latae, subdistantes, marginibus gelatinosae. Sporae 6-7.5 x 4-5 µ, ellipsoideae, punctatae. Basidia 30-35 x 6-7 µ, di- et tetraspora. Pleurocystidia desunt; cheilocystidia hymenialia, 25-48 x 4-6 µ, filamentosa; tramalia gelatinosa, 46-70 x 4-7 µ, filamentosa demum cylindrica. Cuticula ex hyphis repentibus composita, hyphas erectas sine colore gerens, 2.5-3 µ latas. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Mt. Shasta, Calif., June, 1954, W. B. Cooke 29548.

Pileus 6-12 mm broad, yellow, white-tomentose, at first cupulate, then expanding, margin incurved. Context medium thick; odor none.

Lamellae white, then yellow, finally pale brownish, subdistant, narrow to medium broad, edges more or less gelatinous.

Spores 6-7.5 x 4-5 µ, ellipsoid, inequilateral in profile, punctate. Basidia 30-35 x 6-7 µ, 2-4-spored. Pleurocystidia none; cheilocystidia of two types: (a) hymenial, 25-48 x 4-6 µ, filamentous, flexuous, at times clavate, apices rounded, or rarely forked; (b) tramal, gelatinous, 46-70 x 4-7 µ, filamentous, cylindric, or bottle-shaped, or more or less gelatinous. Gill trama slightly interwoven, hyphae 4-7 µ broad. Pileus trama interwoven. Lactifers abundant in the pileus trama. Cuticle a zone of repent hyphae, the zone 30-60 µ thick, bearing a turf of colorless hyphae, 2.5-3 µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On bark of conifer logs, California and New Hampshire, June and September.

Material Studied: CALIFORNIA: Cooke 29548, type (MICH), from Mt. Shasta, leg. W. B. Cooke, June, 1954; NEW HAMPSHIRE: Miller 408 (MICH).

Observations: The characteristics of C. mucidifolius include its yellow pileus, white-tomentose surface, and its gelatinous gill-edges and tramal cheilocystidia.