Cortinarius orellanus

Cortinarius orellanus is a warm-toned, dry-capped webcap of broadleaved woodland in the warmer parts of Europe. Like all members of Cortinarius it produces a cobwebby cortina between cap margin and stipe when young, and like all of them it drops rusty brown spores that stain the veil remnants and the upper stipe.

It belongs to a compact group of tawny to orange-brown webcaps with dry, matt, finely scaly caps and thick, widely spaced gills. The combination of foxy colouring, a bluntly convex to low-umbonate cap and a stipe that tapers downward and lacks contrasting veil belts is the practical signature of the species.

It is essentially a southern and central European fungus of warm, continental woodland, thinning out sharply toward the north and reaching the edge of its range in southern Britain, where records are few and localised.

Cap

3-8 cm across, convex when young, flattening with age and often keeping a low broad umbo rather than a sharp point. The surface is dry and matt, finely fibrillose and breaking into small appressed scales toward the centre, coloured tawny orange-brown to foxy red-brown, sometimes with a paler ochre margin.

Gills

Adnate and emarginate, thick, broad and conspicuously distant, so the spaces between them are easy to see. The colour runs from ochre-yellow through cinnamon to a saturated rust brown at maturity, with slightly paler, minutely uneven edges.

Stipe

4-9 cm long, firm, usually tapering somewhat toward the base rather than swelling into a club. It is yellowish-brown on a paler ground and finely silky-fibrillose overall, with at most faint yellowish fibrils and no crisp contrasting girdles. The cobwebby cortina leaves a rust-dusted zone in the upper part.

Flesh & spore print

Flesh is pale yellowish to ochre, slightly darker in the stipe base, and does not change colour when cut. The spore print is rusty brown, the spores broadly ellipsoid to almond-shaped and distinctly warted.

This webcap grows with broadleaved trees, most often oak and beech, and also with birch, hornbeam and sweet chestnut. It favours acid to neutral soils in warm, well-drained woodland, and often fruits on sloping ground, along woodland banks and in open glades rather than in dense shade. Fruitbodies come up singly or in small loose groups.

The season runs from late summer into autumn. Distribution centres on central, southern and southeastern Europe, extending into France, Germany and Poland; it is rare and local in Britain, with a handful of southern records, and is largely absent from the boreal north where its conifer counterpart takes over.

Cortinarius orellanus is an ectomycorrhizal partner of broadleaved trees. Its hyphae wrap the short roots of oak and beech in a dense mantle and grow between the outer root cells to form a Hartig net, the interface where mineral nutrients drawn from the soil are traded for tree sugars. This partnership improves the host's access to phosphorus and nitrogen and buffers it against drought on thin, well-drained soils.

The fungal network is perennial and can persist under one stand of trees for decades, fruiting only when late-season rain follows warm weather. Because it depends on established woodland with an intact litter layer, it is a useful indicator of long-settled, unimproved broadleaf forest.

Cortinarius rubellus is the nearest relative in appearance but grows with conifers on damp mossy ground, has a sharply pointed cap and shows distinct pale yellow fibrillose belts around the stipe. Cortinarius cinnamomeus is much smaller and more slender, with crowded saffron to golden-yellow gills rather than thick distant cinnamon ones.

Cortinarius bolaris also has a pale-toned cap dappled with coppery-red scales and flesh that yellows then reddens when cut, quite unlike the unchanging ochre flesh here. Tawny Gymnopilus species can resemble it in colour but have crowded gills, a membranous rather than cobwebby veil and a brighter orange spore deposit.