Velvet Rollrim

The Velvet Rollrim is among the easiest large gilled fungi to name in coniferous woodland, thanks to a single unmistakable feature: the thick, off-centre stem is covered in a dense, dark brown to nearly black velvety pile, like the nap of old upholstery. Nothing else of similar size and habitat carries this.

It belongs to Tapinella, a small genus separated from Paxillus on the basis of its brown-rot decay ability and its wood-dwelling habit. Both genera share the paxilloid gill structure, in which the gills are soft, deeply decurrent, forked and interconnected near the stem, and can be scraped or peeled away from the cap flesh in a sheet, a trait shared with the boletes to which they are distantly related.

The species sits at an interesting evolutionary junction. Despite having gills, it is grouped with the Boletales rather than with the ordinary gilled mushrooms, and its rough, inrolled, suede-like cap gives it a look closer to a bolete turned inside out than to a typical woodland agaric.

Cap

The cap is large and fleshy, 5-25 cm across, convex at first with a strongly inrolled margin, later flattening and often becoming depressed, funnel-shaped or lopsided and kidney-shaped where it grows from the side of a stump. The surface is dry, matt and finely velvety like suede, ochre-brown to rusty or dark chestnut-brown, sometimes cracking into patches in dry weather.

Gills

Gills are deeply decurrent, crowded, soft, and conspicuously forked and cross-veined near the top of the stem where they form a network. They are cream to pale yellow-ochre, deepening with age and bruising darker brown where handled. As in all paxilloid fungi, the whole gill layer can be lifted away from the cap flesh with a fingernail.

Stipe

The stem is very thick, 3-10 cm long and 1-4 cm wide, usually eccentric or entirely lateral, solid, and clothed in dense dark brown to blackish velvety tomentum from base to apex. This is the definitive field character.

Flesh and spore print

Flesh is thick, firm and pale yellowish to cream, discolouring brownish slowly when cut or bruised. The spore print is yellowish-brown to ochre.

This fungus is tied to conifer wood. It fruits on and around old stumps, on buried roots, on partly rotten logs and on sawdust-rich ground in plantations and natural coniferous forest. Pine and spruce are the commonest hosts, with fir and larch also used. Fruit bodies often emerge from soil a short distance from the visible stump, connected to buried root wood below.

It is widespread through the temperate and boreal northern hemisphere, including Europe, northern Asia and North America. Fruiting occurs from summer into autumn, typically as solitary specimens or small clustered groups, and the tough fruit bodies persist for several weeks, sometimes blackening as they age.

The Velvet Rollrim is a saprotroph that causes brown rot in conifer wood. It removes cellulose and related carbohydrates while leaving lignin largely intact, so the residual wood becomes brown, crumbly and cracked into cubical blocks. This is a different decay pathway from the white rots produced by most gilled wood fungi, and it leaves behind a long-lasting carbon-rich residue in the forest soil.

Because it exploits stumps and buried roots, it is a characteristic species of managed and previously felled conifer stands, where cut stumps provide a large and durable food source. The brown crumbly residue it generates holds water well and becomes a seedbed and rooting medium for mosses, conifer seedlings and other forest-floor organisms.

Paxillus involutus shares the inrolled margin, decurrent peelable gills and brown cap, but its stem is central, comparatively slender, and pale brown with no velvety black covering, and it grows on soil in association with birch and other broadleaved trees. Its gills bruise rusty-brown far more readily.

Tapinella panuoides grows on conifer wood too but is completely stemless, forming small fan-shaped brackets with strongly crisped and forked gills. Hygrophoropsis aurantiaca has forking decurrent gills as well, but is bright orange, thin-fleshed and small, with a white spore print. Lactarius species can be brown and funnel-shaped, but their flesh is brittle and granular and they exude latex when cut, which this species never does.