Scarlet Waxcap

Hygrocybe coccinea belongs to the waxcaps, a group of small, brilliantly coloured, soft-fleshed agarics in the family Hygrophoraceae. The defining feel of the group is in the name: the gills are thick, rather widely spaced, and have a distinctly waxy or greasy texture when rubbed between finger and thumb. Waxcaps carry a white spore print and gills that are typically broadly attached to the stem, often with a short decurrent tooth.

The scarlet waxcap is one of the reddest of the red species and among the most frequently encountered. Its cap begins as a deep blood-red or crimson hemisphere, spreads to a flattened disc, and pales through orange-red toward the margin as it ages and dries. Unlike some of its relatives it never blackens, and unlike others it never develops a dry, scurfy cap surface.

Waxcaps as a whole are strongly associated with old, unfertilised, closely grazed or mown grassland, and their presence is used across Europe as a signal of grassland that has escaped agricultural improvement. Sites carrying a good suite of waxcaps are treated as habitats of conservation importance, and the scarlet waxcap is one of the species most likely to be seen on such ground.

Cap

2-5 cm across, occasionally to 7 cm, at first a neat hemisphere or bell, then convex and finally flat with a low broad umbo or a slightly depressed centre. The surface is a rich blood-red to scarlet, smooth, moist and slightly greasy when damp, becoming shiny and often fading to orange or orange-yellow from the margin inward. The margin is even and only faintly translucent-striate in wet weather.

Gills

Thickish, distinctly waxy, moderately spaced, broadly adnate and usually running down the stem in a short decurrent tooth. They are red to orange-red across the face, generally paler and more yellow along the edge and toward the base, and the spaces between them are strongly veined in mature specimens. They do not blacken with age or handling.

Stipe

2-6 cm tall, 3-10 mm thick, cylindrical or slightly compressed and grooved, smooth, dry and even in texture. It is coloured like the cap or slightly more orange, characteristically fading to yellow or whitish at the very base, and it becomes hollow with age. There is no ring and no volva.

Flesh and spore print

The flesh is thin, soft and brittle, reddish-orange beneath the cap surface and paler within, with no strong colour change on cutting. The spore print is white. There is no distinctive odour.

This is a grassland species of short, nutrient-poor, unimproved turf: old pasture, hill grazing, coastal cliff-top swards, churchyards, well-established lawns and mossy banks. It also appears in the grassy openings of upland woodland and in dune grassland. Consistently it avoids ground that has been fertilised, ploughed or reseeded, and it does best where moss is abundant and the sward is kept low by grazing or mowing.

Fruiting is late in the year, typically from late summer through autumn and often continuing until the first hard frosts of early winter. It is widespread across Europe, where it is one of the commoner waxcaps, and occurs across much of North America; similar-looking red waxcaps in other continents may represent distinct but closely related species.

The ecological role of waxcaps was long assumed to be simple decomposition of grassland litter, but stable isotope work and the failure of the group to grow on ordinary organic substrates suggest a biotrophic lifestyle instead, with the mycelium apparently obtaining carbon through an association with mosses or the roots of grassland plants. Whatever the exact mechanism, the mycelium is slow-growing, long-lived and highly sensitive to soil disturbance and added nitrogen and phosphorus.

That sensitivity is why waxcap grasslands recover so poorly once ploughed. A site may carry an accumulated assemblage of waxcaps, earthtongues, club fungi and pinkgills built up over a century or more, and the scarlet waxcap is a characteristic member of that community. Fruit bodies are soft and short-lived, releasing white spores over a few days before collapsing into the turf.

Hygrocybe punicea is the largest of the red waxcaps, reaching 12 cm across, with a more blood-red to crimson cap that is greasy and streaky, gills that are more thickly waxy, and a strongly fibrous, longitudinally streaked stem with a conspicuously white base. Hygrocybe splendidissima has a drier, less greasy cap, an even scarlet colour that fades more slowly, a rounded rather than compressed stem, and a honey-like odour as it dries.

Hygrocybe miniata is much smaller, with a dry cap surface that is finely scurfy or minutely scaly under a lens rather than smooth and greasy. Hygrocybe conica, the blackening waxcap, has a sharply conical red or orange cap and bruises and ages black throughout, a change the scarlet waxcap never shows.