The North American Species of Crepidotus

1. Crepidotus cinnabarinus Pk., Bull. Torrey Club 22: 489. 1895.

Illustration: Fig. 34.

Pileus 5-15 mm broad, scarlet to cinnabar-red, conchate to reflexed dimidiate or reniform, becoming more or less plane, surface dry, fibrillose, somewhat glabrescent, margin even.

Lamellae rather broad, subdistant, sinuate to base of pileus, brownish when dried, scarlet on the flocculose or fimbriate edges.

Stipe slight, lateral, and minutely reddish-tomentose, or lacking entirely.

Spores (6) 7-9 (10) x 5-6 µ, oval and pointed at apiculate end as seen in face view, subellipsoid, punctate, thin-walled, many remaining collapsed in KOH. Basidia 20-32 x 7-8 µ, 2-4-spored. Pleurocystidia none; cheilocystidia 30-63 x 5-11 µ, fusoid-ventricose, clavate, cylindric, or bottle-shaped, apices subacute thin-walled, hyaline in KOH, at times extending up the sides 100 µ. Gill trama of hyaline subparallel to interwoven, thin-walled hyphae. Pileus trama of two regions: a lower half of compactly interwoven, hyaline hyphae, 4-8 µ broad and an upper loosely arranged turf, with long hyphae having pinkish, yellowish, or fuscous content when revived in KOH, 150-350 x 3-8 µ, the terminal elements often as clavate-cylindric end cells or pileocystidia ; no incrustations observed. Clamp connections absent.

Habit, Habitat, and Distribution: On basswood and poplar (Tilia and Populus), Michigan, Ohio, and Alabama, summer; also Denmark, on beech.

Material Studied: MICHIGAN: Peck's type (NYS), collected by L. N. Johnson, Ann Arbor, September 24, 1894; Univ. of Mich. Herb. 1847, iso-type.

Observations: This species is rare. It was originally found in Michigan, has rarely been reported from Ohio and Alabama, and is even more rare in Europe, having been reported from Denmark (Møller, 1946). The red color of this species is distinctive.