Suede bolete

Description

The suede bolete has a cap 3–10 cm across, velvety, matt, most often olive-brown, which in dry weather cracks into patches, revealing yellow flesh. Underneath are large, angular, yellow pores that usually do not change colour when damaged. The stem is slender, yellow-brown, without a ring, and has white mycelial threads at the base.

It grows in deciduous and coniferous forests, thickets, less often in parks, most often under oaks, but also hornbeams and beeches. In Poland it is common.

It is very easy to confuse with the red cracking bolete and other similar species; mushroom pickers often call them all "zajączki". If you are not sure of the species, do not pick or eat it.

Identification features

Cap

Diameter 3–10 cm (exceptionally up to 20 cm); hemispherical when young, flattened when older, margin inrolled for a long time. Skin velvety or felty, matt, cannot be peeled off; in dry weather it cracks into patches. Colour most often olive-brown, sometimes yellow-brown or grey-brown; forms: pale yellow (var. luteolus), reddish-brown (var. rubrotinctus).

Hymenophore (underside of the cap)

Tubes 5–20 mm, yellow, with age green-yellow to olive-brown, initially attached and slightly decurrent, later free. Pores large, angular, irregular, pale yellow then greenish-yellow; they do not change colour when damaged (according to some descriptions they may turn slightly blue), in older ones they may turn grey.

Stem

Height 5–13 cm, thickness 1–3 cm, slender, cylindrical, solid, narrowed at the bottom, notched at the top. Colour yellow to yellow-brown or red-brown; longitudinal darker streaks or a net pattern with very elongated meshes may be present. No ring. The mycelial threads at the base of the stem are white — an important identification feature.

Flesh

White or cream with a yellow tinge, darker above the tubes. In the cap soft, fleshy, turns blue when pressed (according to some descriptions); in the stem fibrous, hard, pink or red in the lower part. The smell is sometimes unpleasant, at the base resembling iodoform (according to some descriptions taste and smell slight). Do not taste the flesh.

Spore print and spores

Spore print brown-olive to olive-brown. Spores large, spindle-shaped to ellipsoid, 10–15 × 4–5.5 µm. Under SEM ornamentation is visible on the surface.

Habitat and distribution

Ecology. Mycorrhizal fungus with a broad range of trees; mainly with oaks, less often with hornbeams and beeches, in Mediterranean countries with sweet chestnut; according to some descriptions also with conifers and heathers.

Distribution. Widespread in the northern hemisphere (Eurasia, North America; according to some descriptions also Australia), practically absent in the southern one. Common in Poland, in coniferous and deciduous forests, thickets, less often in parks. It is not legally protected in Poland.

Fruiting. No unambiguous data (according to some descriptions autumn); in Poland usually summer–autumn.

What can it be confused with?

• Xerocomellus chrysenteron (red cracking bolete) — More cracked cap, paler pores and a reddish tinge on the stem.
• Xerocomus ferrugineus (coarsely netted bolete) — Olive-brown cap; mycelium at the base of the stem yellow, whereas in the suede bolete it is white. Grows under conifers.
• Xerocomellus pruinatus (matt bolete) — Pores turn blue when pressed.
• Imleria badia (bay bolete) — Wider stem, darker cap sticky when wet, finer pores that turn blue when pressed.

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

• Described by Carl Linnaeus in 1753 as Boletus subtomentosus; since 1888 it has borne the generic name Xerocomus (from Greek xeros "dry" and kome "hair").
• It is the type species of the genus Xerocomus.
• David Arora jokingly called it the "boring brown bolete".
• The English name "yellow-cracked bolete" refers to the yellow flesh visible in the cracks of the cap.