Tacked milk cap or Ugly milk cap

The cap is 5–15 cm across, occasionally bigger, and fleshy. Young caps are convex with an inrolled margin, then flatten and sink in the centre, and old ones become shallow funnels with a wavy edge.

The colour is lead grey with a lilac or violet tinge, sometimes with darker spots when young. With age it fades to yellowish, flesh pink or brownish. Concentric zones are faint or absent. In wet weather the surface is very slimy; in dry weather it's smooth and shiny.

The cap is 6–15 (up to 20) cm across, making this a large, fleshy milk cap. It starts convex with an inrolled, fuzzy margin, then flattens and finally becomes funnel-shaped with a sunken centre. The colour is dark olive, olive-black or brownish-black; young caps have a yellow-green tinge, old ones are almost black. In wet weather the surface is very sticky and slimy; in dry weather it's shiny, with darker concentric zones. In young mushrooms the margin is densely downy.

The gills are crowded and thin, attached to the stem or running slightly down it. They're whitish at first, then cream and ochre, and old ones can show rusty spots.

Milk drying on the gills leaves grey-green or bluish-green marks, one of the best clues to this species. The spore print is cream to yellowish.

The gills are crowded, narrow, adnate or slightly decurrent, pale yellow to cream, taking on a dark olive tinge with age. Where damaged they darken to brown or black, a characteristic reaction. They exude white milk. The spore print is cream.

The stem is 4–8 cm tall, up to 12 cm in big specimens, and 2–3 cm thick. It's cylindrical or slightly thicker towards the base, slimy, and the same colour as the cap or paler, with a yellowish tint.

It becomes hollow with age. There is no ring and no volva.

The stem is 3–8 cm tall and 1–3 cm thick, cylindrical or thickening toward the base, solid when young and often hollow later. It's paler than the cap, olive-yellow to dingy olive, often with characteristic dark “scrobicules” (sunken pits). It's also sticky in wet weather. There's no ring and no volva.

The flesh is white to creamy, brittle and almost cheese-like. Broken flesh oozes plenty of white milk that slowly turns yellow in the air and then dries to grey-green granules. The milk tastes mild at first, then very acrid and bitter.

The flesh is whitish to yellowish and firm, slowly darkening to grey-brown when cut. Any damage releases plenty of white milk that doesn't change colour in the air but leaves dark stains on the mushroom. With alkali (KOH) it turns violet-black, another diagnostic feature.

The smell is faint, and in many specimens barely noticeable; some people pick up slightly fruity or herby notes. That sets it apart from the fenugreek milk cap, which smells strongly of hay and burnt sugar as it dries.

The smell is faint, neutral, slightly resinous; old mushrooms can smell dirty and earthy. Raw, the flesh and milk taste extremely acrid, bitter and hot. Do not taste it raw.