The North American Species of Crepidotus

94. Crepidotus cinnamomeus sp. nov.

Illustration: Fig. 166.

Pileus 8-20 mm latus, sessilis, dimidiatus vel inaequalis, obscuro-albus deinde cinnamomeus, fibrillosus. Lamellae confertae vel densae, angustae demum medio-latae, pallidae deinde cinnamomeae vel rubido-brunneae. Sporae 5-6.2 x 3.3-4 (4.2) µ, ellipsoideae, punctatae. Basidia 22-28 x 4-6 µ, di- et tetraspora. Pleurocystidia desunt; cheilocystidia 32-42 x 5-8 µ. Cuticula sine magno discrimine, hyphas erectas sine colore gerens. Fibulatae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Priest Lake, Idaho, Oct. 1, 1956, A. H. Smith 53816.

Pileus 8-20 mm broad, sessile, dimidiate to irregular, margin often lobed, surface dull white becoming flushed cinnamon, tomentose near and over basal area, somewhat appressed fibrillose toward the margin. Context white, thin and pliant; odor and taste none.

Lamellae close to crowded, narrow to moderately broad, adnate to the pseudostipe, pallid when young becoming cinnamon to darker reddish brown when mature, edges even.

Stipe lacking or present only as a rudimentary pseudostipe.

Spores 5-6.2 x 3.3-4 (4.2) µ, ellipsoid in face view, subinequilateral in profile, punctate, double-walled, brown in 2% KOH. Basidia 22-28 x 4-6 µ, 2-4-spored. Pleurocystidia none; cheilocystidia 32-42 x 5-8 µ, cylindricsubcapitate, ventricose or clavate with a slender protruding neck, at times constricted and irregular in shape. Gill trama interwoven, hyphae 4-7 µ. Pileus trama interwoven. Cuticle not greatly differentiated from the trama, the surface bearing a tangled trichodermium, the hyphae colorless, apices not coiled. Clamp connections found on hyphae of the epicutis and of the gill trama, and at the base of the basidia.

Habit, Habitat, and Distribution: On birch branches, Idaho, October.

Material Studied: IDAHO: Smith 53816, type, from Priest Lake, Oct. 1, 1956.

Observations: This species is related to C. variabilis, differing in its colors and its cheilocystidia.