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Page number:64 
Remarks (internal):The multiple circular pilei arising from a common stem make this a very distinct species. The sclerotia have been used in China for medical purposes (Zhao & Zhang 1992). The micromorphology and ultrastructure of the sclerotia is given by Guo & Xu (1991). 
Description type:Non-original description 
Description:Polyporus umbellatus Fr. Fig. 19 Syst. Mycol. 1:354, 1821.
Basidiocarps annual, stipitate, arising from a sclerotium with numerous, more or less circular, centrally stipitate pilei arising from a common, strongly branched stipe, total width and height up to 50 cm; the individual pilei partly imbricate, 1-3(4) cm in diameter, flat, margin thin and entire, deflexed in dry specimens, fleshy when fresh, hard and brittle when dry; upper surface glabrous or with very minute adpressed squamules giving the surface a finely spotted appearance (lens), ochraceous to greyish brown, smooth when fresh, wrinkled when dry; pore surface white, cream or straw coloured, pores angular, elongated towards the stipe, 1-3 per mm, on the stipe more irregular, split and partly sinuous, up to 2 mm wide, tube layer concolorous with the pore surface, up to 2 mm thick; context white to cream, dense, up to 3 mm thick; stipe thick at the base, up to 3 cm in diameter, thinner towards the pilei and richly branched, white to cream or pale straw-coloured, in the upper parts covered with strongly decurrent pores.
Hyphal system dimitic; generative hyphae hyaline, with clamps, in the context thinto slightly thick-walled, diameter very variable, partly narrow, partly large and wide with conspicuous clamps, up to 12 µm in diam; in the trama more narrow and rarely above 6 µm; skeleto-binding hyphae scattered and restricted to the trama, thick-walled to solid, hyaline, up to 17 µm in diam, tapering down to about 2 µm in the tips; some gloeoplerous hyphae also present. Basidia clavate, 2-4-sterigmate, 35-45 x 6-9 µm, with a basal clamp. Basidiospores cylindric, 7.5-10 x 3-4 µm.
Cultural characteristics. See Nobles 1948, 1958, 1965, Petersen & Gordon 1994.
Substrata. On the ground from a sclerotium close to stumps of hardwoods such as Alnus, Carpinus, Castanea, Fagus, and Quercus. The last genus seems to be the favourite host. A few times it has also been reported under Picea and Pinus.
Distribution. Circumpolar, but evidently rare everywhere. Reported from India (Bakshi 1971).

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