Humpback brittlegillRussula caerulea

The humpback brittlegill (Russula caerulea, synonyms R. amara, R. sardonia var. amara) is a distinctive pine-forest brittlegill with a pronounced pointed bump on the cap and violet-azure-chestnut coloring. The Latin epithet caerulea means "azure, deep blue", a nod to the bluish-violet tone of the cap. Its Ukrainian name, "buhorchata" ("bumpy"), points to the diagnostic feature — a sharp papillate bump in the center of the cap, which is especially pronounced in young specimens (unlike other brittlegills, whose caps are convex to flat).

Cap 3-8 cm across, conical-convex with a sharp bump when young, becoming flat and spreading with age, but the bump remains. Color dark violet-azure with a purple-chestnut tint, richer in the center, paler and faded toward the edge. In wet weather the cap is sticky and slimy.

Edible, but of modest culinary value because of the slightly bitter taste of the flesh, especially in the stem. Foragers rarely pick it because of its small size, infrequent occurrence and mediocre taste — the bitterness disappears only with prolonged boiling. The literature lists it as "edible, category 3", some sources as "conditionally edible".

The essential check is a taste test: bite off a tiny piece of the gill edge (1-2 mm), hold it in your mouth for 30 seconds: slightly bitter and mild — that's R. caerulea (edible); burning-acrid — that's R. queletii, R. sardonia or another acrid violet brittlegill (DO NOT EAT).

Diagnostic features: (1) a sharp papillate bump in the center of the cap; (2) violet-azure-chestnut coloring with a bluish tint; (3) grows in pine forests (a mycorrhizal partner of pine); (4) spore print yellow-ochre; (5) a mild, slightly bitter taste, with no sharp burning aftertaste; (6) a faint fruity smell, with a hint of coconut in young specimens.

In Ukraine, Russula caerulea is common in pine forests: the Carpathians, Prykarpattia, Polissia, and in places the forest-steppe in pine stands. Season: August — October.