Mycena galopus var. leucogala, sometimes referred to as the Dark Milking Bonnet, is a striking variety of the common Milking Bonnet distinguished by its darker tones and frequent occurrence on burnt or decaying woodland debris. This slender, delicate mushroom features a conical to bell-shaped cap that ranges from dark brown to nearly black, sometimes showing bluish or sepia shades, and a long, thin stem that releases a characteristic white milky fluid when broken. Typically found among both coniferous and deciduous litter, and occasionally in moss or fire-scorched areas.

Cap conical to bell-shaped when young, later becoming more flattened with a slightly depressed centre. It is sulcate and translucent-striate, at first pruinose and dull, sometimes with a faint sheen. The surface is dark brown to nearly black at the centre, often appearing bluish grey or bluish black when fresh. Towards the margin it is dark sepia-brown. The flesh is thin and whitish. Gills 15–18 reaching the stipe, ascending, narrowly adnate to shortly decurrent with a small tooth, becoming interveined with age. They are white when young, later turning greyish or brownish with a whitish edge. Stem slender, hollow, equal or slightly compressed, straight to curved, pruinose when young and gradually glabrescent except near the apex. It exudes a distinct milky white fluid when broken. The colour is dark brown above, almost black towards the base, which is densely covered with coarse whitish fibrils. The stem has no ring. Spore print white.

Microscopic Features: Spores are smooth, ellipsoid to cylindrical, measuring 10–14 × 5–6 μm, and amyloid. Basidia are 4-spored. Cheilocystidia are fusiform to lageniform with long necks, 39–95 × 8–18 μm, often striate and occasionally with lateral or apical outgrowths.

Mycena galopus var. leucogala on the mycena.no Web site.