Surprise Webcap

The Surprise Webcap earns its name in a single movement: an unremarkable dull olive-tawny cap is lifted, and the underside is a shock of blood-red gills. It belongs to the brightly pigmented group of webcaps formerly placed in Dermocybe, whose species carry red, orange or yellow anthraquinone pigments, but unlike its all-red relatives it confines the pigment almost entirely to the gills.

It is one of the commonest webcaps of managed conifer forest on poor sandy soils, often fruiting in large numbers along ride edges and among heather. Because the cap colour is so muted, and because the fruitbodies are small and half-buried in needle litter, it is far easier to find by looking under caps than by scanning the ground.

Like other webcaps it makes a cobwebby cortina in youth and sheds rusty brown spores, which slowly dull the brilliance of the gills as the season advances.

Cap

2-6 cm across, conical to convex and flattening with a persistent low umbo. The surface is dry, matt and finely silky-fibrillose, coloured olive-brown, yellow-brown or dull tawny, often a little darker at the centre, with no trace of red.

Gills

The key character. Adnate, fairly crowded and moderately broad, coloured a saturated blood-red to deep cinnabar when young, in vivid contrast to the drab cap. With maturity the falling rusty spores mute them to a brownish red, but the red tone remains obvious, especially at the edges.

Stipe

3-8 cm long, slender and equal or slightly tapering, coloured yellowish-olive to buff and clothed in fine paler yellowish fibrils. The cortina is yellowish and leaves an indistinct fibrillose zone that becomes rust-dusted; yellowish mycelial strands often cling to the base.

Flesh & spore print

Flesh is thin, pale yellowish to olive-buff in cap and stipe, reddish only in the gill trama, and does not change when cut. The spore print is rusty brown, with small ellipsoid, finely roughened spores.

This webcap favours acid, sandy, nutrient-poor ground under conifers, and is one of the characteristic fungi of pine and spruce plantations, heathy conifer scrub and dune woodland. It also occurs with birch on similar soils. Fruitbodies come up gregariously among needle litter, mosses, heather and bilberry, and are frequent along the sunlit margins of forest tracks.

The season is long, from late summer through to late autumn and sometimes into early winter in mild spells. It is widespread and common across northern and central Europe, including Britain and Ireland, and occurs widely in the conifer forests of North America.

Cortinarius semisanguineus is ectomycorrhizal, forming sheathed root tips and a Hartig net with pines, spruce and birch. This exchange is particularly important on the leached sandy podsols where it thrives, since the fungal network greatly extends the volume of soil from which nitrogen and phosphorus can be gathered and passed to the host.

The red anthraquinone pigments concentrated in the gills are thought to act as a deterrent to invertebrate grazers and are the reason the species has long been used as a natural dye for wool, producing tones from pink through rust to olive depending on the mordant. Colonies are perennial and persist for many years in stable plantation soils, fruiting freely after autumn rain.

Cortinarius sanguineus is blood-red throughout, cap and stipe included, rather than red only on the gills. Cortinarius cinnamomeus has a similar olive to cinnamon cap but its gills are saffron-yellow to golden orange, never red.

Cortinarius malicorius has deep orange gills and typically a distinct orange veil zone near the stipe base. Cortinarius croceus is the closest match in cap colour but has ochre-yellow to yellow-brown gills with at most a faint reddish tint, and a more olive-yellow stipe.