Velvet Bolete

The Velvet Bolete is the odd member of Suillus that at first glance does not look like one at all. Instead of the slick, glutinous cap typical of the slippery jacks, it has a dry, finely tomentose surface breaking into small appressed scales, giving a matt, suede-like texture that only becomes slightly tacky in prolonged wet weather.

Its pore surface is also atypical for the genus: small, closely packed and coloured a dull cinnamon or olive-brown rather than bright lemon, so the underside looks dark compared with its relatives. Combined with a stout, ringless, undotted stalk and flesh that stains blue, these characters make the species recognisable at a distance once known.

It is a fungus of the boreal and northern temperate pine zone, and in Scandinavia and the Baltic it is among the most abundant large fungi of dry heath forest, often fruiting in great numbers over sheets of lichen and moss.

Cap

5-15 cm across, thickly convex then broadly flattened. The surface is dry and finely woolly-felted, breaking up into small darker appressed scales over an orange-ochre, yellow-brown or dull tawny ground; in old or very wet specimens it may smooth out and become slightly viscid. The margin is even and incurved for a long time.

Pores

Small and round to slightly angular, dull cinnamon-brown, olive-brown or greyish-ochre from an early stage, darkening with age and often bruising faintly blue-green where pressed. The tube layer is adnate to slightly decurrent.

Stipe

5-10 cm tall and 1.5-3 cm thick, stout, solid, cylindrical or slightly swollen below, coloured pale yellow-ochre to buff and sometimes flushed brownish at the base. There is no ring and no glandular dotting.

Flesh & spore print

The flesh is firm for a Suillus, pale yellow, and typically turns weakly blue when cut, most reliably in the cap flesh directly above the tubes and in the stalk base. The odour is faint and slightly metallic. The spore print is olive-brown.

Ectomycorrhizal with pines, especially Scots pine, on acidic, sandy or peaty soils. It is characteristic of dry heath forest, lichen-rich pine woodland, dune plantations and bog margins, frequently fruiting among heather, crowberry and reindeer lichens.

The season runs from midsummer through autumn, often extending later than most pine boletes. It is widespread and abundant across northern and central Europe and northern Asia, becoming scarcer southwards, and follows planted pine into other regions.

As with other members of its genus, Suillus variegatus forms ectomycorrhizal sheaths around pine root tips, exchanging mineral nutrients and water for photosynthetic carbon. On the nutrient-poor sands and podzols it favours, this partnership is a major route by which pines obtain nitrogen and phosphorus.

Its mycelium runs extensively through the litter and upper mineral soil, producing successive flushes of fruiting bodies from the same network over many years. In boreal pine forest the species contributes substantially to below-ground fungal biomass and to the turnover of nutrients held in litter.

Suillus bovinus shares the habitat but is slimmer and paler pinkish-buff, with a smooth to slightly greasy cap and wide, compound, decurrent pores; its flesh does not blue. Suillus granulatus has a distinctly glutinous cinnamon cap, bright lemon pores and glandular dots on the stalk.

Imleria badia, the Bay Bolete, can be confused at a distance but has a smooth chestnut cap and pale yellow pores that stain strongly blue-green at a touch, far more vividly than the Velvet Bolete's dull cinnamon tubes. Various Xerocomellus species have dry cracking caps but are smaller, with wider yellow pores and a red-tinged stalk.