Crimson Waxcap Identification Guide

The First Impression

You will almost always meet this species standing in open turf rather than under trees. The setting is a short, mossy, unimproved sward: an old churchyard, a lawn that has been mown for a century but never fed, a coastal cliff-top, a dune slack, a hill pasture grazed by sheep. Autumn rain has been falling for a fortnight, the grass is soaked, and from twenty paces you see a red mushroom that is simply too big to be one of the ordinary small red waxcaps. That combination of large size, a slightly greasy blood-red gloss, and open grassland is the first filter, and it removes most of the field before you have even knelt down.

Kneel anyway. Everything that follows depends on lifting one whole fruitbody, base included, out of the moss without snapping it.

Reading the Cap

Measure it. A mature cap runs 4 to 12 cm across, occasionally larger, which is roughly double the span of the common red waxcaps growing beside it. The shape begins bluntly conical or bell-shaped, then expands to broadly convex, usually keeping a low, rounded hump. As it expands the margin often splits radially, lifts, and becomes lobed or wavy, so old caps look torn and untidy.

Feel the surface. In damp weather it is viscid, and even in dry spells it retains a distinctly greasy, polished sheen rather than a matt or fibrous texture. Colour is deep blood-red to scarlet at first, fading unevenly through orange-red to orange and finally to dull yellow-orange at the margin, so a single cap can carry three tones at once. Try lifting a shred of the cuticle at the margin with a thumbnail: it peels a short way as a thin gelatinous film.

Reading the Gills

Turn the cap over. The gills are the reason this whole group is called waxcaps. They are unusually thick for their depth, soft, and slightly translucent, and if you rub one between finger and thumb it smears like a candle rather than tearing like paper. They are distant to subdistant, so you can count them without a lens, and short gills alternate with full-length ones.

Attachment matters. Here the gills are broadly adnexed to adnate, very often running down as a short tooth on the stipe, and the spaces between them at the cap edge are frequently bridged by low cross-veins. Colour is orange-yellow to reddish-orange, typically with a paler yellow edge that shows well when you tilt the cap into the light.

Stipe, Base and Flesh

The stipe is stout, 5 to 12 cm tall and 1 to 2.5 cm thick, sometimes flattened, grooved or slightly club-shaped. It is dry, never slimy, and its surface is strongly fibrous with coarse longitudinal fibrils that often twist. Colour is red to orange over most of its length, streaked with yellow.

Now the single most useful character in the whole species: the extreme base. The lowest 5 to 15 mm is white, abruptly and cleanly so, as if the stipe had been dipped in chalk. This is why you must extract the fruitbody whole rather than pinching off the cap. Older stipes become hollow and split lengthwise. There is no ring and no volva.

Split the fruitbody down the middle. The flesh is whitish to pale yellow-orange, reddish immediately under the cuticle, and thick over the centre of the cap. Watch the cut face for two minutes. Nothing happens. Bruise the gills and stipe firmly with a fingernail and watch again: they may darken slightly with handling, but they do not turn grey or black. That negative result is worth doing deliberately, because the blackening waxcaps are the commonest source of confusion.

Taking a Spore Print

Cut the cap free, lay it gills-down on a sheet of dark card with a strip of clear glass or foil underneath one half, cover with an upturned cup to keep humidity in, and leave it somewhere cool for four to twelve hours. Waxcaps drop quickly and generously. The print is pure white, at most with the faintest cream cast, and the distant gills reproduce as a coarse radiating pattern that is itself a clue. Under a microscope the spores are smooth, colourless, broadly ellipsoid, roughly 8 to 11 by 4.5 to 6 micrometres, and do not react with iodine.

Substrate, Season and Ecology

Nothing about this species involves wood. It arises directly from turf, usually where the sward is short, mossy and nutrient-poor, and it keeps company with other waxcaps, pinkgills, club and coral fungi and earthtongues. That assemblage is a habitat signature in its own right: if you are standing in a genuine waxcap grassland, the identification becomes far more plausible.

The season runs from late summer to early winter, peaking in mid to late autumn. The underlying mycelium is long-lived and slow to establish, which is why the same patches of turf produce year after year and why ploughing or heavy fertilising eliminates the fungus for decades. Waxcaps are no longer regarded as simple litter recyclers; isotope studies point to a biotrophic relationship with grassland plants or with the mosses among which they grow, though the details remain unresolved.

Separating the Look-alikes on Morphology

The Scarlet Waxcap, Hygrocybe coccinea, is the nearest problem. It is smaller, typically 2 to 5 cm, its gills are more broadly attached with a more pronounced decurrent tooth, and, decisively, its stipe is red essentially all the way down, showing at most a small white fleck at the very point of attachment rather than a clean white boot.

The Splendid Waxcap, Hygrocybe splendidissima, is comparably robust but its cap is dry to only slightly greasy, more orange-red than blood-red, its stipe is coloured to the base, and drying specimens develop a honeyed smell.

The Blackening Waxcap group, Hygrocybe conica and relatives, can start scarlet, but the flesh, gills and stipe bruise grey and eventually coal-black. Handle a cap roughly and wait ten minutes and the question answers itself.

Hygrocybe intermedia is orange-red and similarly large, but its cap surface is dry, minutely fibrillose or scurfy rather than greasy, and its stipe is fibrillose-scurfy too.

Cuphophyllus species growing in the same turf have strongly decurrent gills and are white, buff or pinkish, never scarlet.

Working Checklist

• Large red cap, 4 to 12 cm, greasy and blood-red fading to orange
• Thick, waxy, distant gills, orange-yellow with a yellow edge
• Stout, dry, coarsely fibrous stipe, red above, abruptly white at the base
• No blackening on bruising anywhere
• White spore print
• Short, mossy, unfertilised grassland; autumn