Cinnamon Webcap Identification Guide

The First Impression and the Habitat

Cinnamon Webcap is a mushroom you almost walk past. In a damp spruce or pine forest, among deep feather moss, Sphagnum hummocks and bilberry, all you see from above is a small, dull, olive-brown cone. There are dozens of such caps in any autumn conifer wood. The identification begins the moment you tip one over, because the gills are far brighter than anything the cap promised: saffron to orange-yellow, glowing against the drab cap.

The habitat matters. Think acid, damp, mossy ground under Norway spruce or Scots pine, boggy woodland margins, the edges of peaty flushes, and mossy birch on the same soils. The species is mycorrhizal, so it comes up from moss and soil, scattered or in loose troops, sometimes many dozens through a single moss carpet, and it returns to the same patches annually.

Reading the Cap

Caps are two to five, occasionally six centimetres across. They begin conical to convex and expand to broadly convex or nearly flat, almost always keeping a distinct pointed or low broad umbo at the centre.

The surface is dry - never viscid - matt, and finely radially fibrillose or silky, so raking low light across it shows fine streaks running from centre to margin. The very centre can be minutely scaly in older specimens.

Colour is where the common name comes from: olive-brown, tawny, cinnamon-brown or dark yellow-brown, generally darker at the disc and often with an olive-yellow cast towards the margin. It is not strongly hygrophanous, so a wet cap and a dry cap look broadly similar apart from a slight dulling.

Gills: The Character That Stops You

The gills are adnate, moderately crowded, and fairly narrow. In young fruit bodies they are bright saffron-yellow, chrome-yellow or orange-yellow - an unexpectedly strong colour under such a plain cap - and this is the single best field character.

As spores mature, rusty cinnamon-brown deposit gradually clouds that yellow, so old specimens can look simply brown. Always seek out buttons and young caps in a troop to read the true gill colour, and look at the gill edge with a lens, where a paler yellow rim often survives.

Stipe, Cortina and Base

The stipe is three to eight centimetres long and three to eight millimetres thick, cylindrical, slender, often curved where it has grown through moss. It is yellow-olive to yellow-brown, silky-fibrillose along its length, and frequently marked with pale yellowish fibrillose girdles left by the veil. There is no membranous ring.

The veil is the genus character and is worth hunting for. In young fruit bodies a cobwebby cortina stretches from the cap margin to the stipe like a fine web; the moment you handle the mushroom it collapses onto the stipe as a band of loose fibrils. On mature specimens, falling spores dust that band rust-brown, giving an obvious rusty fibrillose zone. Finding either the intact web or the rusty band is how you confirm a webcap in the field before printing anything.

Dig the base rather than pulling. It is not bulbous and has no volva, and it commonly sits in a tuft of yellowish mycelium binding moss and needle litter.

Interior Colour

Split the mushroom lengthways. The tissue is yellow to olive-yellow, strongest in the stipe cortex and beneath the cap cuticle and paler towards the centre. That persistent yellow tone, rather than the white or brown of most brown-spored mushrooms, is an important supporting character.

Colour change on cutting is minimal - perhaps a slow browning in the base. There is no latex. The odour is faint, slightly earthy or radish-like, and easiest to detect by crushing a piece of stipe.

A drop of potassium hydroxide on the cap surface or cut tissue produces a dark red to blackish-red reaction from the pigments in this group, a quick way to confirm you are among the yellow- and red-gilled webcaps rather than the dull brown ones.

Taking a Spore Print

Cut the stipe off flush with the gills and place a mature cap gill-side down on white paper under a cover for four to eight hours. The deposit is rust-brown to cinnamon, thick and unmistakable, and it explains why the gills lose their yellow with age.

Rusty print plus cortina places the mushroom in Cortinarius with certainty; the yellow gills and yellow tissue then take you to the small group this species belongs to. Microscopically the spores are small, ellipsoid and finely warted, roughly six to eight by four to five micrometres.

Substrate and Season

The fungus is mycorrhizal with conifers, above all Norway spruce and pine, and also occurs with birch on peaty, acid ground. It favours damp, mossy, nutrient-poor sites: moss carpets, Sphagnum edges, bilberry-rich forest floors and the wet margins of forest tracks.

The season is late summer through late autumn, peaking after sustained rain. Troops are often extensive, with fruit bodies at every stage scattered through the moss, which is convenient because you need both buttons and mature caps to read the full character set.

Separating the Look-alikes on Morphology

Cortinarius semisanguineus is the closest match in stature, cap colour, stipe colour and habitat - everything except the gills, which are a deep blood-red rather than saffron-yellow. Young material is essential, because both fade to brownish with spore load.

Cortinarius malicorius has orange to orange-red gills, an altogether more orange aspect, a darker olive cap and orange-tinted tissue in the cap margin.

Cortinarius croceus is very close indeed, with a darker, more olive-brown cap and gills that tend towards a duller olive-yellow; separation often rests on gill hue and on spore dimensions under the microscope.

Cortinarius sanguineus is dark blood-red throughout, cap as well as gills, with dark red tissue.

Cortinarius uliginosus is a brighter orange-brown to coppery species of wet willow and alder carr rather than mossy conifer forest.

Gymnopilus species share rusty spores and yellow tones but grow directly on wood, particularly conifer stumps and logs, have brighter yellow-orange caps, and do not present a true cobwebby cortina in the same way.

Hypholoma species have purple-brown to blackish spore deposits, tufted growth on wood, and no cortina.

Galerina species are smaller and more slender, with smooth hygrophanous caps, brown gills from the start with no yellow phase, and often a distinct small membranous ring.

Working Checklist

Dry, finely fibrillose, umbonate olive- to cinnamon-brown cap of two to five centimetres; saffron to orange-yellow gills when young; slender yellow-olive fibrillose stipe with pale girdles and a cobwebby cortina that later becomes a rusty band; yellow tissue; dark red reaction with alkali; rust-brown spore print; mycorrhizal in damp mossy conifer woodland in autumn.