North American species of Crepidotus, by L.R. Hesler and Alexander H. Smith.

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North American Species of Crepidotus

MATERIAL STUDIED: MICHIGAN: Smith 50945, type, from Mud Lake
Bog, Cheboygan County, Oct. 9, 1955.
OBSERVATIONS: The distinctive features of C. cinereipallens include the
grayish pileus and gills, the absence of epicuticular hyphae on the pileus,
and the broad cheilocystidia.
113. Crepidotus obscurus sp. nov.
Illustrations: Figs. 187a, b.
Pileus 5-30 mm latus, albus deinde brunnaceus, fibrillosus, margine lobatus.
Lamellae latae, confertae, albae deinde brunneae. Pseudostipes 2-3 mm X 0.5-0.7 mm,
albus, centro aberrans. Sporae 7-9 X 4.5-5.5 [t, ellipsoideae, rugoso-verrucosae.
Basidia 22-26 X 7-8 Iu, tetraspora. Pleurocystidia desunt; cheilocystidia 24-38 X
4-8 i,, clavata, cylindrica, ventricosa, vel 33-55 X 10-28,I, clavata, napiformia vel
sphaeropedunculata. Cuticula ex hyphis repentibus composita, hyphas erectas gerens.
Fibulatae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Ann Arbor,
Mich., Sept. 15, 1938, A. H. Smith 10963.
Pileus 5-30 mm broad, at first pure white and white-fibrillose or
pubescent throughout, finally subglabrescent near the margin, at maturity
sordid brownish, applanate, large pileus variously wavy or lobed, at times
almost orbicular. Context thin, soft, whitish; odor and taste mild.
Lamellae broad, close, adnate-to or free from the stipe, white then
sordid brown.
Stipe a pseudostipe, 2-3 mm long, 0.5-0.7 mm thick, white, appearing
eccentric, not attached to substratum.
Spores 7-9 X 4.5-5.5 /t, ellipsoid, obscurely wrinkled-verrucose, thickwalled. Basidia 22-26 X 7-8 /, 4-spored. Pleurocystidia none; cheilocystidia
of two general types: (a) clavate, ventricose, cylindric, 24-38 X 4-8 /t;
(b) broadly clavate, napiform to sphaeropedunculate, 33-55 X 10-28 /.
Gill trama slightly interwoven to subparallel, hyphae 7-10(14) /x broad, of
relatively short cells. Pileus trama interwoven. Cuticle of repent hyphae,
bearing scattered or gregarious, erect hyphae, which may be branched.
Clamp connections present.
HABIT, HABITAT, AND DISTRIBUTION: On basswood, Michigan, September.
MATERIAL STUDIED: MICHIGAN: Smith 10963, type, from Ann Arbor,
Sept. 15, 1938.
OBSERVATIONS: The cheilocystidia are strikingly different in shape from
those of C. subverrucisporus, and the spores less conspicuously wrinkledverrucose.
114. Crepidotus subverrucisporus Pilat var. subverrucisporus
Illustrations: Figs. 29, 189.

Pileus 4-20(30) mm broad, conchate, then flabelliform to reniform or