The North American Species of Crepidotus
9. Crepidotus uber var. uber (B. & C.) Sacc. Syll. Fung. 5: 878. 1887.
Agaricus (Crepidotus) uber, B. & C., Amer. Acad. Arts Sci. Proc. 4: 117. 1868.
Crepidotus sulcatus Murr., Mycologia 5: 29. 1913.
Pileus 1.5 cm broad, white to yellowish-fuscous, flabelliform to orbiculate-reniform, laterally sessile, delicately membranous-fleshy, surface glabrous, viscid, margin not involute.
Lamellae moderately close, broad, argillaceous-fuscous to ferruginous.
Spores 6-8 x 4.5-5.5 µ, mostly 7 µ or less in length, ellipsoid, at times slightly inequilateral in profile, smooth, double-walled, thick. Basidia 28-34 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 26-35 x 4-6 µ, clavate or obclavate, few, mostly collapsed against the gill edge. Gill trama subparallel, hyphae 3-5 µ broad. Pileus trama radially interwoven, appearing more or less as cells in tangential sections. Cuticular zone and pileus trama more or less uniformly gelatinous, no distinct gelatinous stratum on the surface, as in C. mollis.
Habit, Habitat, and Distribution: In shady woods, Bonin Islands and Cuba; Singer (1947) reports it from Florida.
Material Studied: BONIN ISLANDS: the type, no. 46 (K) collected by Charles Wright, Expedition of 1853-56; CUBA: Underwood and Earle No. 761, type of C. sulcatus (NY) collected at the base of El Yunque Mt., Baracoa, March, 1903.
Observations: This species was compared with Murrill's type of C. sulcatus, and they agree in all essential microscopic characters. The sulcate-striate margin of the pileus in C. sulcatus is not mentioned in the original description of C. uber, but this is hardly regarded as a specific difference. This species differs from mollis in its lack of both brown incrusted hyphae and a gelatinous, cuticular stratum. Singer (1947) holds that uber is the southern form of C. mollis, and that C. citri Pat. is a synonym of C. uber. We found the type of C. citri inadequate for microscopic study of the pileus.