The North American Species of Crepidotus

114. Crepidotus subverrucisporus var. subverrucisporus Pilát, Studia Botanica Čechoslavaca 10: 151. 1949.

Illustrations: Figs. 29, 189.

Pileus 4-20 (30) mm broad, conchate, then flabelliform to reniform or suborbicular, dry, white, pubescent, margin incurved. Context thin; odor and taste mild.

Lamellae broad to medium broad, close to nearly subdistant, white becoming clay color, edges white-crenulate.

Stipe none or a temporary pseudostipe present.

Spores 7-9 (10) x 4.5-5.5 (6) µ, ellipsoid, inequilateral in profile, wrinkled-verrucose. Basidia 24-33 x 6-8 µ, 2-4-spored. Pleurocystidia none; cheilocystidia 37-70 x 5-8 µ, cylindric, slender bottle-shaped with a neck, or ventricose. Gill trama subparallel to slightly interwoven, hyphae 4-10 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of colorless hyphae, 2-5 µ broad, at times the hyphal cells inflated and then 6-9 (14) µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On hardwood, Michigan, Colorado, and Oregon, June-October; also Europe.

Material Studied: COLORADO: Smith 52903; MICHIGAN: Smith 57889, 66383; OREGON: Smith 19443; CZECHOSLOVAKIA: Pilát 149034 (type, PR, from Chrustenica, Bohemia, July 20, 1946), 189766, 189768 (PR).

Observations: The type is characterized by white pileus, white then clay-color gills (no pink tints), spores 7-9 (10) x 4.5-5.5 (6) µ, wrinkled-verrucose, and rather long, slender, often slender-ventricose cheilocystidia. We have encountered a form with pinkish gills, similar spores, and usually shorter cheilocystidia. This we have described as var. roseifolius; and another form with notably larger spores we have named var. megalosporus. Favre (1960) says the spores in deposit are cinnamon brown-mars brown of Ridgway, and that the spore wall is not echinulate but distinctly verrucose, the warts low. Since he found the spores to measure 8-11 (13) x 5-6.5 µ, he assumes his collection may be a macrosporic form, and refers to Pilát (1950: 164).