The North American Species of Crepidotus

89. Crepidotus rhizomorphus Burt, Ann. Missouri Bot. Garden 10: 181. 1923.

Pileus 5-7 mm broad (dried), sessile, "pinkish buff" (dried), glabrous, membranous, margin even, entire.

Lamellae radiating from a central point, ventricose, snuff brown. Rhizomorphic strand, about 1 mm broad, bone brown, extends along the grass culm.

Spores 5-7 x 3.5-5 µ, ellipsoid, smooth, brown. Basidia 17-20 x 4-5 µ. Pleurocystidia none; cheilocystidia 20-30 x 5-6 µ versiform (fusoid, bottle-shaped, irregularly clavate). Gill trama slightly interwoven, hyphae 3-5 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing at intervals small clusters of colorless, erect pileocystidia , cylindric-capitate, clavate, at times with a septum cutting off a rounded terminal cell. Clamp connections present.

Habit, Habitat, and Distribution: On culm of grass, Hawaiian Islands, July.

Material Studied: HAWAII: F. L. Stevens 940, type, Hawaii, July 23, 1921 (111-30029).

Observations: This species is closely related to C. albidus, from which it is distinguished by its brown rhizomorph and its pileocystidia.