Hymenophore effused, to 7 x 4 cm., 0.5-1 mm. thick, at first pallid green or dingy grey, blackening where bruised, finally becoming almost black upon the surface; margin lifting, 2-3 mm. wide, byssoid, dingy grey to some shade of greyish brown, irregular; surface even, or undulate, dissepiments not toothed. Pores not in strata, round or slightly angular, 5-7 to mm., or 3-5 to mm. when young, in section isabelline, greyish or dingy brown, to 0.8 mm. deep, 150-200 µ diameter; dissepiments 25-150 µ thick, apices of compact woven hyphae, slightly velutinate, coloured black by a mucilaginous precipitate covering hyphal walls and filling interstices. Context 200-500 µ thick, of hyaline hyphae mostly parallel at the base and in dissepiments, sclerotioid between base and pores and with bands of black mucilage lying between hyphae, crystals abundant, massive; generative hyphae 3-6 µ diameter, lumen 2-3 µ, branched, septate, clamp connections present, in old specimens a few of the basal hyphae with tinted walls. Basidial type clavate, basidia clavate, 8-12 x 4-5 µ, forming a compact palisade. Spores elliptical, ovate, or pip-shaped, 3.5-4 x 2-2.5 µ, hyaline, smooth.

Characters of the species are the dark colour of the hymenium, blackening when old or bruised, sclerotioid context, monomitic hyphal system, and small ovate or elliptical spores. Although superficially the plant might be sought under species with brown coloured hyphae, it belongs to the hyaline series, since the hyphae are hyaline, the dark colour being produced by quantities of fuscous mucilage embedding hyphae of the context and dissepiments.

The surface of the hymenophore in different collections may be pallid yellow, greenish yellow, fuscous, or black, sometimes most colours appearing in one collection. When bruised or rubbed the surface rapidly changes to fuscous or black, a feature separating the species from Polyporus adustus, with which it may be confused, since both possess a monomitic hyphal system, large hypha, and abundant clamp connections. P. curreyana differs, additionally, in being resupinate, possessing a pallid irregular margin, larger pores, different colour, and thinner walls of the generative hyphae.