How to tell Velvet rollrim from Brown rollrim

Cap 5–15 cm across, convex in young mushrooms, then depressed or funnel-shaped. Surface smooth, hairy-felty in young ones, almost bare in mature ones, olive brown or yellowish brown, sticky in wet weather. The margin stays rolled under for a long time — a characteristic feature.

The cap is large: usually 5–15 cm, and some reach 30 cm. It starts out convex, then flattens, sinks in the center and often becomes tongue-shaped or wavy, while the margin stays rolled under for a long time.

The color is rusty brown, ochre brown or walnut brown, often with darker patches. The surface is dry and finely felted, like suede to the touch.

Gills crowded, thin, ocher-yellow or olive, easily separating from the flesh when pressed, browning when damaged. They run down the stem. This tendency to brown when pressed is a useful identification feature.

The gills are crowded, cream-yellow or pale ochre, browning with age. They run down the stem and near it they fork and join up with cross-veins. They darken when pressed.

The spore print is yellowish brown.

Stem 3–8 cm tall, 1–2 cm thick, firm, solid, cylindrical or tapering downward, the same color as the cap or slightly paler. No ring and no volva.

The stem is short and very thick: 2–7 cm tall, sometimes up to 12 cm, and 1.5–3.5 cm wide, up to 5 cm on big specimens. It's central or off to one side, cylindrical or widening toward the base, and often sunk into wood or moss.

The key feature of the species: the stem is densely covered in dark brown, almost black velvety down. There is no ring.

Flesh yellowish cream or brownish, firm in young ones, looser in mature ones. Browns when damaged. Has a slightly acrid or sourish taste. Does not exude milk.

The flesh is firm, whitish, yellowish or ochre, and darkens on exposure to air. The taste is sometimes bitterish, and unpleasant in old specimens. Insects rarely eat it: when the fruit body is damaged, it produces substances that deter insects.

Smell sourish and pleasant, like fruit or vinegar, especially in mature mushrooms. This neutral, even pleasant smell is exactly what helped the mushroom pass as edible for so long.

The smell is faint and unremarkable. So you can't recognize the velvet rollrim by smell; look at the stem and at where the mushroom is growing instead.