The North American Species of Crepidotus

66. Crepidotus albatus sp. nov.

Illustrations: Figs. 18, 135, 136.

Pileus (3) 6-20 mm latus, sessilis, ungulatus deinde flabelliformis demum semiorbicularis, albus, albo-fibrillosus. Lamellae albae deinde "pinkish cinnamon," confertae, angustae demum medio-latae. Sporae 6-8 (9) x 4-5.5 µ, ellipsoideae, punctatae. Basidia (18) 25-30 x 6-8 µ tetraspora. Pleurocystidia 24-26 x 5-8 µ; cheilocystidia 31-70 x 6-12 µ. Cuticula ex hyphis repentibus composita, hyphas erectas sine colore gerens, 2-3(5) µ, latas. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Mio, Mich., Aug. 14, 1963, A. H. Smith 67203.

Pileus (3) 6-20 mm broad, sessile, ungulate, soon becoming flabelliform or semiorbicular, dry, white, white-villose or pubescent to fibrillose, base white-strigose, matted-fibrillose toward the margin, extreme margin inrolled and frosted, basal hyphae quickly yellow in 2% KOH. Context white or pallid, thin, firm; odor and taste none.

Lamellae narrowly adnate, white then pinkish-cinnamon, finally cinnamon, close, narrow to medium broad, edges even or fimbriate.

Spores 6-8 (9) x 4-5.5 µ, ellipsoid, only slightly inequilateral in profile, punctate. Basidia (18) 25-30 x 6-8 µ, 4-spored. Pleurocystidia 24-46 x 5-8 µ, flask-shaped, tapering above or with a neck; cheilocystidia 31-70 x 6 -12 µ, flask-shaped, with a neck, often flexuous. Gill trama interwoven, hyphae 5-10 µ broad. Pileus trama interwoven. Cuticle of repent hyphae bearing a turf of tangled, colorless hyphae, 2-3 (5) µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On hardwood logs, Michigan and Tennessee, June-August.

Material Studied: MICHIGAN: Smith 49909, 67203, type, on Tilia, Mio, Aug. 14, 1963; TENNESSEE: Hesler 3658.

Observations: The white villose-pubescent pileus, and the large, conspicuous, flask-shaped or cucurbitiform pleurocystidia and cheilocystidia, and ellipsoid, punctate spores are distinctive characters of this species. This is related to C. fragilis Joss., in which the pileus is larger, the spores somewhat longer, amygdaliform, and smooth.