Stocking Webcap

The Stocking Webcap takes its name from the most distinctive feature of the genus's veil architecture: the outer veil does not merely fibrillate away but clings to the lower stipe as a smooth white sheath, ending abruptly in a firm upturned rim or collar that looks exactly like the top of a rolled stocking. Nothing else among the common brown webcaps shows this so crisply.

It sits among the telamonias, the dry-capped webcaps with hygrophanous flesh, but it is stouter and firmer than most of that group, with a dull violet-brown cap, thick violet young gills and a sweetish smell. The violet tones are strongest at the stipe apex and in fresh gills, fading as rusty spores accumulate.

It is a widespread autumn fungus of mature broadleaf woodland, particularly on the richer, better-drained soils that support beech and oak, and often appears in troops along woodland paths and slopes.

Cap

4-9 cm across, convex and often bell-shaped when young, expanding to broadly convex or flat with a low broad umbo. The surface is dry, finely silky-fibrillose and hygrophanous, greyish violet to lilac-brown when moist and drying to a duller tan or clay-brown from the centre. Fine pale veil fibres may fringe the margin in youth.

Gills

Adnate to emarginate, thick, broad and notably well spaced, distinctly violet to greyish lilac when young and darkening through clay to rusty cinnamon as spores mature. The edges stay paler and are slightly uneven, and the spacing is a helpful contrast to the crowded gills of many relatives.

Stipe

5-10 cm long and firm, more or less equal or slightly swollen below, violet at the apex and paler beneath. The lower half is wrapped in a smooth white to pale lilac sheath which stops abruptly in a raised, often flaring rim, giving the booted or stockinged appearance. Above the rim the cortina leaves a rusty fibrillose zone.

Flesh & spore print

Flesh is firm and pale, tinted violet in the stipe apex and cap, unchanging when cut, with a sweetish aromatic smell. The spore print is rusty brown; spores are almond-shaped and coarsely warted.

This webcap grows with broadleaved trees, above all beech and oak, and also with hornbeam, birch and hazel, on neutral to base-rich, well-drained woodland soils. It fruits singly, in scattered groups or in loose troops in deep leaf litter, and is often plentiful on slopes, banks and the sides of woodland paths where litter is well aerated.

The season runs from late summer through autumn, with the main flush in the middle of the season. It is widespread and frequent across Britain, Ireland and continental Europe, and comparable populations are recorded from temperate North American broadleaf forest.

Cortinarius torvus is ectomycorrhizal, forming a sheath and Hartig net on the fine roots of beech, oak and other broadleaved hosts. Through that interface the fungus supplies nitrogen, phosphorus and water drawn from a hyphal network reaching far beyond the root zone, receiving photosynthetic sugars in return. On mature beech and oak stands, webcaps are among the more numerous root symbionts.

The conspicuous outer veil, unusually persistent for the genus, protects the developing gills while the fruitbody expands and then remains as the characteristic stocking. Colonies are perennial and long lived, and their fruiting closely tracks autumn rainfall and falling soil temperature; spent fruitbodies are rapidly colonised by fungus gnats and litter invertebrates that recycle the tissue back into the humus.

Cortinarius anomalus has a similar dull lilac-brown cap and violet young gills but is more slender, with crowded gills and one or two ochre-yellow veil bands on the stipe instead of a smooth white sheath with a rim. Cortinarius alboviolaceus has a paler, pearly silvery cap and a club-shaped stipe with a silky veil that never forms a crisp collar.

Cortinarius evernius is a conifer species, much more slender, with a darker date-brown hygrophanous cap and whitish veil bands rather than a boot. Cortinarius hemitrichus grows with birch and has a smaller cap flecked with fine white veil scales, plus a thin stipe with white girdles.