Redlead Roundhead Identification Guide

The Scene Where You Find It

The Redlead Roundhead is a mushroom of managed landscapes. Look in fresh bark mulch around municipal plantings, woodchip beds in parks and gardens, the chipped-up remains of a felled tree, path surfacing in botanical gardens, and the edges of nursery beds. It is far less common in undisturbed forest, and its spread across the world has largely followed the trade in landscaping mulch.

The first impression is unmistakable colour. A scattering — often a crowd — of small, glossy, brick-red to scarlet-orange caps sits low over the chips, looking almost lacquered when wet, and the contrast with the drab brown mulch is loud enough to spot from a moving car. The second impression, on approach, is of a mismatch: the caps are hot orange-red but the gills beneath are dark, dusky purple-grey.

Fruiting is gregarious to clustered, usually in autumn and into early winter in temperate regions, or in the cool wet part of the year in Mediterranean climates. Flushes appear within a week or two of mulch being laid down and watered.

Reading The Cap

Caps are 1 to 8 cm across, most often in the 2 to 5 cm range. They start hemispherical to convex — the roundhead of the name — and flatten with age to broadly convex or plane, sometimes with a slight central hump.

Colour is bright orange-red, brick-red, scarlet or occasionally a duller rusty-orange, typically deepest over the disc and paler toward the margin. Sun and age bleach the colour toward orange-buff, so darker specimens in shade give the truest reading.

The surface is smooth and distinctly viscid to sticky when moist; touch it with a dry fingertip and litter will adhere. In dry weather it becomes shiny rather than tacky.

Now examine the margin with a lens. Young caps carry scattered whitish veil remnants — small cottony patches, flecks or a fringe hanging from the cap edge. These wash off in rain, so absence in an old specimen means nothing, but their presence on fresh caps is a good supporting character.

Reading The Gills

Tip the cap over and the colour story changes completely. In very young buttons the gills are pale grey, buff or faintly olive. As spores mature they darken through smoky grey to dark purple-brown, chocolate-purple or nearly black-purple.

The gills are attached to the stalk, broadly adnate to slightly notched, and moderately crowded. Look along a gill edge with a lens: the edges are commonly paler, whitish or minutely fringed, standing out as a fine light line against the dark face. That contrast between a dark gill face and a pale edge is a helpful detail.

The Stalk, Veil And Base

The stalk is 2 to 10 cm long and 2 to 10 mm thick, roughly equal or slightly thickened downward, dry, and whitish to pale yellowish at the apex, darkening to yellow-brown, orange-brown or rusty toward the base. It is hollow or stuffed with a loose pith.

Below the midpoint you will usually find a ring zone rather than a true skirt: a fibrillose, sometimes slightly flaring band where the partial veil broke, often stained darker by falling spores until it reads as a dark belt around a pale stalk. Fine whitish fibrils typically streak the stalk below it.

Then get the base out intact. Dig with your fingers under the chips and lift the whole cluster. In this species the base is bound into the mulch by conspicuous white cords and mycelial threads — rhizomorphs — that run out through the chips and often knot fragments of wood together. Those white strands, against orange caps and purple gills, complete the picture.

Flesh And Colour Change

Cut a fruit body lengthwise. The cap flesh is whitish to pale yellowish and thin; the stalk flesh is whitish above and dingy yellow-brown toward the base. There is no dramatic reaction on cutting — no blueing, no reddening, no milk. Handled or bruised areas may darken slowly to brownish, and the stalk base often looks rusty-stained simply from age and soil contact.

Odour is mild and unremarkable, and should not be leaned on.

Taking A Spore Print

This is the step that converts a probable identification into a firm one. Cut a mature cap free and lay it gill-side down on white paper — white is essential here, because the whole point is to read a dark deposit. Cover with a bowl and leave three to eight hours.

The print is dark purple-brown to purple-black. Smear the deposit thinly with a knife edge and hold it to the light to judge the tone; a thick pile can look plain black. Rusty-brown, cinnamon or ochre deposits rule the species out immediately, and a pale or white deposit means you are looking at something entirely unrelated.

Substrate, Season And Ecology

This is a wood-litter decomposer, and its substrate preference is narrow and useful: hardwood or softwood chips, bark mulch, sawdust, and woody debris in soil. It is not mycorrhizal, does not fruit in open turf away from woody material, and only rarely appears in undisturbed forest litter. When it does appear in a garden bed, digging usually reveals chips or buried wood beneath.

Native to Australasia, it has become widespread in Europe, North America and elsewhere through landscaping practice, and it now behaves as a reliable member of the woodchip fungal community alongside inkcaps, Agrocybe and Stropharia species. Fruiting is autumn-weighted in cool climates, winter-weighted in warm ones, and closely tied to irrigation as much as to natural rainfall.

Separating It From Look-alikes On Morphology

Wine Roundhead and other Stropharia relatives. Some carry orange-brown to reddish caps, but they tend to have a true membranous ring rather than a fibrillose zone, and often coarser scales.

Leratiomyces squamosus var. thraustus. Closely related and superficially similar in colour, but the cap is more orange to brick and less scarlet, the stalk is conspicuously shaggy with recurved whitish scales below a better-developed ring, and the whole mushroom is taller and more slender. Fruiting is usually on woody debris in forest rather than in landscaping mulch.

Gymnopilus species. Orange to rusty caps on wood, but the gills mature rusty-orange and the spore print is bright rusty-brown rather than purple-black, and the cap is dry and fibrillose rather than viscid.

Pholiota species. Often orange and viscid, but they are usually distinctly scaly, cluster directly on logs and stumps rather than in loose mulch, and drop a plain brown print.

Hypholoma species. Share dark purple-brown spore prints and tufted growth, but caps are yellow, tawny or brick-brown with yellow-green or olive-toned young gills, and they fruit on stumps and buried roots rather than fresh chips.

Small Hygrocybe waxcaps. Bright red and sometimes viscid, but they grow in grassland, have thick waxy widely spaced gills and drop a white print.

A Quick Field Sequence

1. Bright orange-red viscid cap on woodchips or bark mulch, gregarious.
2. Whitish veil flecks at the cap margin on young specimens.
3. Gills attached, ageing dark purple-brown with paler edges.
4. Stalk pale above, yellow-brown below, with a fibrillose ring zone.
5. White cords binding the base into the chips.
6. Spore print dark purple-brown to purple-black on white paper.