Phylloporia ribis

Parasitic species on living bases and stems of Ribes sp., though also occurring on various other woody shrubs, with semicircular, bracket-shaped, flattened basidiocarps 4 to 8 cm wide at the base, dark reddish-brown surface, tiny, almost imperceptible round brown pores (6 to 7 per mm), and a cinnamon-brown context that darkens instantly in KOH.

Hyphal system monomitic; contextual and tramal hyphae thick-walled, dark brown, 4 to 7 µm wide; subhymenial hyphae hyaline, thin-walled, 2 to 3 µm wide; both sparsely septate and clampless.

Hymenial setae absent.

Basidia clavate, 10 to 15 µm long, 4 to 5 µm wide, simple-septate at the base, 4-spored.

Spores subglobose to short-ellipsoidal, minute, smooth, hyaline, moderately thick-walled, pale yellow under the microscope, 3 to 3.5 µm long, 2.8 to 3.2 µm wide, lacking a distinct apiculus, inamyloid in Melzer's reagent.