velvet rollrim

Description

The velvet rollrim is a large, squat fungus with a brown, suede-like cap, usually a dozen or so centimetres across, with an inrolled margin and a depressed centre. Underneath are crowded, cream-yellow gills running down the stem. It is easiest to recognise by its stem: thick, hard, attached at the side or off-centre, and covered with black-brown velvety fur.

It grows from August to October on stumps, roots and rotting wood of conifers, most often pines and spruces, in coniferous and mixed forests. In Poland it is fairly common. It appears singly or in groups, even in drier periods.

Despite its seemingly appetising look, the flesh is bitter and tough, and the fungus is inedible. It is told apart from the brown roll-rim, which grows on the ground and is poisonous, by its black velvety stem and by its growth on wood.

Identification features

Cap

Diameter up to about 20–30 cm (descriptions give different maxima); shape often irregular, depressed in the centre, with an inrolled margin. In young specimens the surface is matt and suede-like, in older ones smooth. Colour ranges from olive through nut-brown and sepia to dark brown, sometimes rusty brown.

Hymenophore (underside of the cap)

Gills crowded, clearly decurrent down the stem (especially in young fruiting bodies), forked, often connected by cross-veins (anastomoses). Initially white or cream-yellow, with age ochre-yellow; they turn brown where damaged.

Stem

Height about 3–7 cm (up to 12 cm according to some descriptions), thickness about 2–4 cm. Solid, hard, resilient, usually eccentric or lateral, covered with a dark brown to black velvety fur. No ring.

Flesh

White or whitish-yellow, juicy, brittle, hard in the stem. Smell: none. Taste bitterish to acrid. The flesh should not be tasted.

Spore print and spores

Spore print brownish, pale ochre to yellowish brown. Spores broadly ellipsoid to roundish, smooth, almost colourless, about 5–7 × 4–4.5 µm (descriptions give different ranges).

Habitat and distribution

Ecology. Saprotroph on dead wood of conifers: on stumps and dead roots, and on rotting wood buried in the ground. Occurs on various tree species, most often on pines and spruces.

Distribution. Europe, North America, also Central America (Costa Rica) and Asia (including Pakistan, China). Fairly common in Poland, in coniferous and mixed forests. It is not legally protected in Poland.

Fruiting. From August to October; fruiting bodies also appear in drier periods, when other fungi do not fruit.

What can it be confused with?

• Paxillus involutus (brown roll-rim) — Grows on the ground as a mycorrhizal fungus, with a central, smooth stem without black fur; cap smaller, rusty brown. It is poisonous.
• Tapinella panuoides — Fruiting bodies fan-shaped or shell-shaped, without a distinct stem, usually much smaller, orange-brown; grows on coniferous wood.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The species name comes from the Latin atrotomentosus – "black-haired", referring to the velvety stem.
• Although it has gills, it belongs to the order Boletales, that is, mainly pored fungi such as boletes.
• Damaged fruiting bodies convert compounds called leucomentins into atromentin and osmundalactone, which deters insects from feeding; as a result the flesh is rarely eaten by insects.
• Andreas Gminder wrote that it has "such a horrible taste that no one has yet managed to prepare it so that it is palatable".