The North American Species of Crepidotus

87. Crepidotus lundellii Pilát apud Lundell & Nannfeldt, Fungi Exsicc. Suecici praesertim Upsalienses No. 220. 1935.

Illustration: Fig. 159.

Pileus 6-17 mm broad, white, drying pale buff or ochre, sessile, dry, at first ungulate or conchate, finally more or less expanded, villose, base strigose or tomentose, margin incurved.

Lamellae whitish, becoming pale brown, narrow to medium broad, nearly close to close.

Stipe none or, if present, inconspicuous and temporary.

Spores 6-8 (8.5) x 4.2-5.2 (5.5) µ, ellipsoid, inequilateral in profile, smooth, wall moderately thick, pale yellowish-brown in 2% KOH. Basidia 20-26 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 22-56 x 4-12 µ, cylindric and at times more or less capitate and constricted, ventricose, clavate. Gill trama subparallel, hyphae 6-9 µ broad. Pileus trama interwoven. Cuticle not differentiated, the surface bearing a turf of colorless hyphae, some narrow (2-4 µ broad), others broad (4-10 µ), the hyphal cells often more or less inflated at the septa, and the terminal elements often as clavate pileocystidia . Clamp connections present.

Habit, Habitat, and Distribution: On hardwood, Michigan and New York, June-September; also Europe.

Material Studied: MICHIGAN: Shaffer 1300 (MICH); Smith 57885; NEW YORK: Bigelow 5057; NETHERLANDS: Bas 10778 (L); SWEDEN: Pilát 149039, type (PR), on decaying Ulmus branches, collected by Seth Lundell, Sept. 15, 1935.

Observations: The spore measurements above are based on Smith's collection No. 57885. In Pilát's type, the spores are 6.5-8.5 (9) x 4.5-5 (5.3) µ; and in Bas' collection from the Netherlands, 6-8.5 x 4.5-5.5 µ. In Pilát's description (1948), he gives the spores 7-10.5 x 5.8-7.5 µ, mostly 8 x 6 µ. But in a study of his type, we found no spores longer than 9 µ. Pilát (1948) discusses variability of the spores, and in some collections he found the spores to be shorter (6.5-7.5 x 4.5-5.5 µ). For these short-spored forms, he has described (1940) C. lundellii var. subglobisporus, based on material from Czechoslovakia and Sweden. C. lundellii var. lundellii is distinguished from C. albissimus by its larger spores. The relationship of C. lundellii var. subglobisporus to C. albissimus is as yet not entirely clear.