The North American Species of Crepidotus

Ex 10. Pleuroflammula dussii (Pat.) Sing., Mycologia 38: 521. 1946.

Crepidotus dussii Pat., Bull. Soc. Myc. Fr. 18: 173. 1902.

Pileus (2)4-10(17) mm broad, convex or reniform, "colonial buff" to "cream color" or "ochraceous buff" to "amber brown," more yellow near the margin, browner toward the disc, "antimony yellow" at the margin, "Sudan brown" on the disc in age, at first fibrillose, then glabrescent, non-viscid. Context yellowish, bitterish.

Lamellae at first almost "amber yellow," the edges more yellow than the olive or brownish sides, finally brown from the spores, comparatively broad (up to 2 mm at maturity), subclose to subdistant, adnexed or when young often emarginate-adnexed.

Stipe up to 2 x 1.5 mm, apex yellowish, below brownish, fibrillose from the veil, glabrescent, at times indistinctly subannulate, curved, eccentric,  becoming sublateral. Veil at first covering the lamellae, at times forming a narrow, indistinct annulus.

Spore deposit: "Brussels brown." Spores 6-8 (9) x 4.5-5.5 (7) µ, ellipsoid, thick-walled, smooth, with an indistinct germ-pore. Basidia 23-27 x 6-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 22-52 x 5-10 µ, variable: clavate, subcylindric, ventricose, subfusoid, subcapitate to appendiculate, spathulate, ampullaceous. Gill trama interwoven. Cuticle a gelatinous zone, more or less 50 µ thick, the hyphae 3-5 µ broad and imbedded in a gelatinous matrix, resting on a hypodermium about 20 µ thick. Clamp connections few and inconspicuous on the epicuticular hyphae.

Habit, Habitat, and Distribution: On dead wood, Guadeloupe; also Florida, June-August.

Material Studied: GUADELOUPE: Patouillard, type (FH), Nos. 25 and 111, collected at Baines-Jaunes.

Observations: Singer (in: Singer and Smith, 1946) proposed the genus Pleuroflammula, and made P. dussii (Pat.) Singer the type species. It differs from Crepidotus chiefly in the presence of a veil. Although Singer (1962) characterizes the pileus of Pleuroflammula as non-viscid, a study of the type of P. dussii shows a gelatinous cuticular zone. In his description he does not mention the gelatinous cuticular zone, but does report incrusted cuticular hyphae. The description of macroscopic characters above is based on that of Singer; and that of microscopic characters is based on the type.