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Page number:233 
Remarks (public):The species is relatively easy to recognize by the small basidiocarp, the black pileus and the pale pore surface. Microscopically the large cylindrical spores are diagnostic. The other Datronia species are separated by much thinner and flexible basidiocarps and a persistently velutinate to tomentose pileus. After examining the type of Trametes nigrescens we concluded that it is a synonym of D. scutellata. 
Description type:Non-original description 
Description:Datronia scutellata (Schw.) Gilbn. & Ryv. - Mycotaxon 22:364, 1985. - Polyporus scutellatus Schw., Trans. Am. Phil. Soc. II, 4:157, 1832. - Trametes nigrescens Bres. Ann Mycol. 3:163, 1905.
Basidiocarps annual, pileate to effused reflexed, dimidiate to almost pendent or broadly attached, tough when fresh. hard when dry, up to 1.5 cm wide, 3 cm long and 3-10 mm thick; upper surface of pileus at first whitish, but soon dark brown to black, margin often remaining paler than basal parts, at first velutinate. but soon glabrous and often slightly sulcate in zones; pore surface white to buff or pale brown with age, pores round to slightly angular, 4-5 per mm. dissepiments often finely farinose; context 1-3 mm thick, dense, wood-colored to pale brown, with a distinct black crust on top; tube layer up to 7 mm thick, cork to wood colored.
Hyphal system trimitic; generative hyphae with clamps, thin-walled. hyaline in context and trama. 2.5-4 µm in diam, pigmented hyphae with clamps present on pileus surface; skeletal hyphae solid, pale yellowish, 2-4.5 µm in diam; binding hyphae of same width as skeletal hyphae, but much more branched.
Cystidia none, fusoid cystidioles present, 20-28 x 5-6 µm, with a basal clamp. Basidia broadly clavate, 4-sterigmate, 20-30 x 7-10 µm, with a basal clamp. Basidiospores cylindrical, thin-walled, hyaline. smooth. negative in Melzer's reagent, 8-12 x 3-4.5 µm.
Type of rot. Causes a white rot in dead hardwoods.
Cultural characteristics. See Campbell 1938; Nobles 1965; Stalpers 1978. Sexuality. Unknown.
Substrata. In Europe known only from Alnus, in other areas known from a number of hardwood genera.
Distribution. In Europe very rare and known only from the Alps in Switzerland and Austria. Cosmopolitan species and widespread in the tropical zone.
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