The North American Species of Crepidotus

75. Crepidotus phaseoliformis sp. nov.

Illustration: Fig. 148.

Pileus 1-3 cm latus, sessilis, convexo-dimidiatus, albidus, fibrillosus. Lamellae "pale tawny," confertae demum subdistantes, latae. Sporae (5.5) 6-8 x 4-4.5 µ, ellipsoideae vel ovoideae ad frontem conspectae, oblique phaseoliformes, planae. Basidia 23-28 x 5-6 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 44-60 (76) x 4-7 µ. Cuticula gelatinosa, hyphas erectas sine colore gerens, 3-6 µ latas. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum in Perry Sound District, Ontario, Canada, Sept. 1919, Kelly 158.

Pileus 1-3 cm broad, sessile, convex-dimidiate with an incurved margin, dull white and unchanging, appressed fibrillose, or when young the fibrils more or less erect. Context white, firm.

Lamellae near pale ochraceous tawny when dried, close to subdistant, broad, edges serrulate.

Spores (5.5) 6-8 x 4-4.5 µ, ellipsoid or more rarely ovoid in face view, phaseoliform or subphaseoliform in profile, smooth, wall moderately thick. Basidia 23-28 x 5-6 µ, 4-spored. Pleurocystidia none; cheilocystidia 44 -60 (76) x 4-7 µ, filamentous to cylindric, apices at times slightly enlarged to subcapitate, often appearing slightly gelatinous. Gill trama with a distinct mediostrate, the hyphae 3-5 µ, broad and slightly interwoven; on either side of the mediostrate the hyphae distinctly gelatinous-the trama appearing bilateral. Pileus trama interwoven and often vesiculose. Cuticle a distinct gelatinous zone, 110-200 µ thick, bearing on its surface a turf of colorless, non-incrusted hyphae, 3-6 µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On birch, Canada, September.

Material Studied: CANADA: Kelly 158, type (MICH), from Perry Sound District, Ontario, Sept. 1919.

Observations: This species is characterized by its phaseoliform, smooth spores, and its gelatinous cuticular zone on the pileus surface.