The North American Species of Crepidotus

117. Crepidotus circinatus sp. nov.

Illustrations: Figs. 191, 192.

Pileus 5-15 mm latus, sessilis, flavido-coriaceus, villosus. Lamellae medio-latae, medio-confertae. Sporae 6-8 x 4.5-6 µ ellipsoideae, punctatae. Basidia 27-34 x 6-7 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 32-56 x 5-11 µ. Cuticula ex hyphis repentibus composita, hyphas erectas, sinuosas et in spiram volutas gerens. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Baker Lake, Wash., Sept. 2, 1941, A. H. Smith 16572.

Pileus 5-15 mm broad, sessile, yellowish buff, villose.

Lamellae medium broad, medium close.

Spores 6-8 x 4.5-6 µ, ellipsoid, inequilateral in profile, punctate. Basidia 27-34 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 32-56 x 5-11 µ, fusoid, clavate, bottle-shaped, apices at times forked or branched. Gill trama interwoven, hyphae 5-9 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of hyphae 5-9 µ broad, random cells with a golden yellow or brownish pigment in 2% KOH, the upper portion of some of the turf hyphae crooked and coiled. Clamp connections present.

Habit, Habitat, and Distribution: On hardwood twigs, Washington, September.

Material Studied: WASHINGTON: Smith 16572, type, from Baker Lake, Sept. 2, 1941.

Observations: Except for colors, this appears to be closely related to C. regularis. It is characterized chiefly by its buff yellow pileus, moderately small spores, and crooked to coiled epicuticular hyphae.