Russula nigricans (Bull. ex Mérat) Fr. Dickblättriger Schwarztäubling, Russule noircissante, Blackening Brittlegill.
Cap 5–20cm across, convex, soon with a deep depression, dirty white, becoming brown and finally black, dry, fleshy, three-quarters peeling; margin incurved at first. Stem 30–80 x 10–40mm, white, then dull brown, finally black, hard. Flesh white, becoming greyish rose on exposure and finally grey to black. Taste slowly hot, smell fruity. Gills adnate, straw to olive, greyish rose on bruising, eventually black, very thick and widely spaced, brittle, with numerous shorter gills between them. Spore print white (A). Spores ovoid with small warts under 0.5µ high, mostly connected by fine lines to form a fairly well-developed, but partial network, 7–8 x 6–7µ. No cap cystidia. Habitat under broad-leaved trees and conifers. Season summer to late autumn. Very common. Edible but poor in taste (Never eat any mushroom until you are certain it is edible as many are poisonous and some are deadly poisonous.) Distribution, America and Europe.