The North American Species of Crepidotus

91. Crepidotus albissimus Murr., Mycologia 35: 530. 1943.

Illustration: Fig. 163.

Pileus 8-12 x 6-8 mm, convex, reniform, dry, silky-fibrillose, very white, unchanging, margin even, incurved. Context white, unchanging.

Lamellae adnate, white, whitish when dry, rather broad behind, medium distant, inserted, edges fimbriate.

Spores 5.3-7 x 3.5-4.5 µ, ellipsoid or subovoid, smooth, pale brown. Basidia 22-28 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 30-83 x 4-7 µ, cylindric, slender-clavate, at times subventricose, apices rounded, or capitate, frequently blunt. Gill trama subparallel, hyphae 3-5 µ broad. Pileus trama distinctive: the inner three-fourths more densely interwoven, the outer one-fourth more loosely organized and pale. Cuticle of several layers of repent hyphae, bearing a turf of slender (2.5-5 µ), colorless hyphae, the terminal elements, in some instances, as more or less clavate pileocystidia . Clamp connections present.

Habit, Habitat, and Distribution: On dead hardwood branch, Florida, June.

Material Studied: FLORIDA: Murrill F 17281, type, from near Gainesville, June 28, 1938.

Observations: This is a smooth-spored, white species, related to C. albidus, but the pileus is very white and silky-fibrillose, and the cheilocystidia are long (up to 83 µ). Although the pileus surface is dry to the touch, the outer fourth of the pileus trama (sections in KOH), appear slightly gelatinous. It is distinguished from C. lundellii by its smaller spores.