Velvet Milkcap

The Velvet Milkcap is one of the most photogenic members of its genus, thanks to the extreme contrast between its almost black, suede-textured cap and stipe and its brilliant white gills and gill edges. The gill edges are often outlined in dark brown, giving mature specimens a pin-striped appearance when viewed from below.

Lactarius lignyotus belongs to a group of dark, dry-capped milkcaps sometimes treated as section Plinthogalus, which also contains L. fuliginosus, L. picinus and L. fallax. All share a matt to velvety, non-viscid cap surface, whitish latex that discolours pinkish or salmon on white flesh, and pale yellowish spore prints.

It is a fungus of cool, humid, mossy conifer forest and is most often found half-buried in deep moss cushions, where its dark cap is easily overlooked until the white gills catch the light. The cap is usually radially wrinkled or corrugated toward the margin, and typically carries a small sharp central point (a papilla or pointed umbo).

Cap

The cap is 3–10 cm across, convex to flat and finally shallowly depressed, but almost always retaining a small sharply pointed central umbo. The surface is completely dry, finely velvety or suede-like to the touch, and often strongly wrinkled or ribbed radially near the margin. Colour ranges from dark sooty brown through chocolate to nearly black, sometimes with a faint reddish or greyish cast; the margin may be paler and is often minutely scalloped.

Gills

Gills are broadly attached to distinctly decurrent, moderately distant, and pure white to cream at first, later becoming pale yellowish as spores mature. The gill edges are frequently darkened brown, contrasting sharply with the pale faces. Bruised or cut gills stain pinkish to salmon.

Stipe

The stipe is 4–12 cm tall and 0.5–2 cm thick, slender, firm, dry and velvety like the cap, and coloured the same sooty brown to blackish. It is often longitudinally wrinkled toward the apex and typically has a narrow whitish zone immediately under the gills. No ring or volva is present.

Flesh, latex and spore print

The flesh is white and brittle, turning pink to salmon-red where cut or where latex touches it. The latex itself is white and unchanging on exposure to air but reddens the white tissue within a minute or two, a key diagnostic reaction. The spore print is pale yellow to ochre; spores are globose to subglobose with high amyloid ridges forming a bold reticulum.

Lactarius lignyotus is mycorrhizal with conifers, particularly spruce (Picea) and fir (Abies), and occasionally with hemlock. It fruits singly or in scattered groups in deep moss, on rotting needle duff and on mossy banks and hummocks in damp, shaded coniferous forest, often in the same mossy patches season after season.

It is a northern and montane species. In North America it occurs across the boreal forest belt, in New England and the Appalachians, the Great Lakes region and in the western mountains; in Europe and Asia comparable populations occur in montane spruce forest, though some of these are now separated as related species. Fruiting is from midsummer to early autumn, and it responds strongly to prolonged wet spells.

Like the rest of Lactarius, this is an obligate ectomycorrhizal symbiont. Its mycelium colonises spruce and fir rootlets, and in the cold, acidic, slowly decomposing needle mats of montane conifer forest it substantially improves the host's access to nitrogen locked up in organic matter. It cannot survive without a living host, so its presence is a direct indicator of established mycorrhizal conifer stands.

The two-part chemical defence of the fruiting body is notable: pressurised laticifers release white latex on damage, and a separate colour reaction rapidly turns the punctured tissue pink-red. Grazing tracks left by slugs and larvae on the cap and stipe are therefore usually outlined in salmon or rust tones, making feeding damage easy to read.

Lactarius fuliginosus is very similar in colour and in its pinking flesh but has a duller, more greyish-brown, less strongly wrinkled cap without the pointed umbo, and grows with broadleaved trees rather than conifers. Lactarius picinus is blacker and more matt, with a smooth rather than corrugated cap and closer gills. Lactarius fallax is close enough to be treated by some authors as a variety of L. lignyotus, but has a more velvety-scurfy black cap and gills that are often less decurrent.

Dark Russula species can look superficially similar from above but produce no latex whatsoever when the gills are cut, and their flesh usually blackens rather than turning salmon-pink.