The North American Species of Crepidotus

43. Crepidotus flexuosus sp. nov.

Illustration: Fig. 99.

Pileus 5-10 mm latus, sessilis, dimidiatus, “pinkish buff," in base "orange buff," siccus. Lamellae confertae, angustae demum medio-latae. Sporae 4.5-5.5 µ, globosae, perparum punctatae. Basidia (27) 33-47 x 5-7 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 38-76 x 3-6 µ. Cuticula ex hyphis repentibus composita, ex hyphis caespitem gerens. Fibulatae adsunt. Specimen typicum in Herb. Univ. Mich., lectum prope Douglas Lake, Mich., Dick Homola, July 22, 1963, A. H. Smith 66846.

Pileus 5-10 mm broad, sessile, dimidiate, "pinkish buff," around the base orange-buff, opaque, unpolished, dry.

Lamellae close, narrow to medium broad.

Spores 4.5-5.5 µ, globose, minutely punctate, yellowish-ochraceous in KOH. Basidia (27) 33-47 x 5-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 38-76 x 3-6 µ, filiform or cylindric, often flexuous or cork screw-shaped, basal portion slightly broader than above, conspicuous. Gill trama subparallel, hyphae 4.5-7 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of septate hyphae, the terminal element more or less aciculate, the penultimate cell usually broad (up to 10-12 µ), not incrusted. Clamp connections present.

Habit, Habitat, and Distribution: On aspen, Michigan, July.

Material Studied: MICHIGAN: Smith 66846, type, on aspen, Rees' Bog, Univ. Mich. Biological Station, Douglas Lake, leg. Dick Homola, July 22, 1963.

Observations: The exceptionally long basidia and the flexuous cheilocystidia characterize this species.