Red cracking bolete

Description

The red cracking bolete (today called suchogrzybek złotopory in Polish) has a matt, dry, finely downy cap, brown to olive-brown, 3–10 cm across. In dry weather the skin cracks into patches, and the cracks show reddish or pale flesh. Underneath are wide, angular, yellow-green pores that turn blue when touched. The stem is yellow just under the cap, usually reddish or brownish lower down.

It grows from June to November in coniferous and deciduous forests and parks, mainly under beeches, pines and oaks. In Poland it is very common.

They cannot always be reliably distinguished without a microscope. The fruiting bodies quickly become wormy and soft; mouldy ones should not be eaten. If you are not sure of the species, do not pick or eat it.

Identification features

Cap

Diameter 3–10 cm; convex or hemispherical when young, then flattened, sometimes slightly depressed. Skin dry, matt, finely downy, brown, yellow-brown, often with an olive tinge, also ochre-grey, red-brown or dark brown. In drought it cracks into patches, exposing flesh from whitish to reddish (according to some descriptions a light red layer under the skin).

Hymenophore (underside of the cap)

Tubes initially pale yellow, later green-yellowish or olive-greenish, turning blue under pressure. Pores of the same colour, wide, angular, sometimes stained brownish, turning blue under pressure.

Stem

Height 4–13 cm (descriptions give different ranges), thickness 1–2 cm, mostly cylindrical, tapering towards the base, often bent. Yellow just under the cap, otherwise usually tinged red or brown (according to some descriptions covered at the bottom with coral-red fibrils), often with longitudinal fibrils. No ring.

Flesh

Hard in young specimens, later soft, watery and quickly decomposing. In the cap yellow, when damaged initially turns blue, then red; in the stem of adult specimens brown-red. Smell faint, taste somewhat sour. Do not taste the flesh.

Spore print and spores

Spore print brownish-olive or olive. Spores narrowly ellipsoid or ovoid-spindle-shaped, smooth, 12–14 × 4–5 µm.

Habitat and distribution

Ecology. Mycorrhizal fungus; grows on the ground under beech, Scots pine, oaks (pedunculate, sessile, scarlet). The fruiting bodies are often attacked by the bolete eater Hypomyces chrysospermus (mouldy ones are not fit to eat).

Distribution. Common throughout the northern hemisphere in the temperate zone, very common in Poland; in coniferous and deciduous forests, parks. Introduced to New Zealand. It may be less common than thought, because it is sometimes confused with the recently recognised Boletus cisalpinus. It is not legally protected in Poland.

Fruiting. From June to November (according to some descriptions from early summer to mid-winter).

What can it be confused with?

• Xerocomellus porosporus (sepia bolete) — No reddish colour in the cracks of the skin and on the stem; reliably distinguishable only by the spores (truncate).
• Xerocomus subtomentosus (suede bolete) — Brighter yellow pores; the cap in older specimens does not crack into patches, and the flesh does not turn blue when pressed.
• Xerocomellus pruinatus (matt bolete) — Darker cap, harder flesh, fruits only in autumn.
• Imleria badia (bay bolete) — The caps are similar; the bay bolete has a cap sticky when wet and the pores turn blue-grey.

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 type species of the genus Xerocomellus, created by J. Šutara in 2008.
• The epithet chrysenteron comes from Greek khrysos (gold) and enteron (intestines).
• In Polish dialect: "czerwona noga" (red foot), "zajączek", "zajęczak".
• The fruiting bodies are often attacked by the parasitic fungus Hypomyces chrysospermus.