Red-capped scaber stalk

Description

The red-capped scaber stalk has an orange-red to brick-coloured cap, a whitish stem covered with scales (turning reddish or darker with time) and small, greyish pores under the cap. The flesh is white and darkens when cut. In Poland it grows from June to October in forests and thickets, usually under aspens.

There are several similar boletes with reddish caps, and they differ mainly in the tree under which they grow (birch, pine, spruce, aspen). So when collecting, it is worth paying attention to the surroundings and to the scales on the stem.

This mushroom requires thorough heat treatment. The flesh turns black when cooked. If you are not sure of the species, do not pick it and do not eat it.

Identification features

Cap

Diameter 3–15 cm. Young ones spherical, then hemispherical, finally low and arched. Colour orange-red, red-orange, dark red or brick-red. Margin thin; the cuticle at the edge of older specimens usually hangs beyond the tubes as a thin membrane.

Hymenophore (underside of the cap)

Tubes greyish with an olive tinge. Pores round, small, at first white, then greyish-ochre, finally olive; may turn olive-brown when pressed.

Stem

Height 5–18 cm, thickness 2–3 cm (descriptions give different height ranges); cylindrical, solid, wider at the base. Whitish, covered with scales that are whitish when young and later orange-red (according to some descriptions the small scales turn brown to black with age). Under the cap the scales remain white for a long time. No ring. According to some descriptions the stem may turn blue-green when damaged.

Flesh

Thick, firm, juicy, white; darkens when cut (first burgundy, then grey- or violet-black). Taste mild, smell indistinct. In older specimens stringy in the stem, soft and watery in the cap. Turns black when cooked.

Spore print and spores

Spore print brown or olive-brown. Spores smooth, yellow-brownish, spindle-shaped: 13–17 × 4–5 µm.

Habitat and distribution

Ecology. Terrestrial mycorrhizal fungus. In Poland, according to some descriptions, it grows exclusively under European aspen; in Europe traditionally associated with poplar, but also recorded under oak, beech, birch, chestnut, willow and linden; in Europe it is not known with conifers. Grows in forests and thickets.

Distribution. Europe and North America (in the latter case, identifications may refer to other species), also Central America and Japan. Widespread but uneven in Central Europe; fairly frequent in Poland. Listed on the red lists of threatened species in Germany and the Netherlands. Not legally protected in Poland.

Fruiting. From June to October.

What can it be confused with?

• Leccinum versipelle (orange birch bolete) — Paler, grows under birches; easiest to tell apart by the black scales on the stem.
• Leccinum vulpinum (pine bolete) — Grows only under pines.
• Leccinum piceinum (spruce bolete) — Grows only under spruces.
• Leccinum albostipitatum — Grows with aspen and has white scales on the stem; not all authors regard it as a separate species.

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 first scientific description dates from 1791 (Bulliard); the Polish name was given by Feliks Berdau in 1876.
• It is on the red lists of threatened species in Germany and the Netherlands.
• European red-capped boletes differ mainly in habitat, and not all authors regard them as separate species; North American specimens may belong to other species.
• The colour of the flesh changes to dark when cut and when cooked, and acid prevents the darkening.