Beechwood Sickener Identification Guide

The First Impression

In a beechwood in late summer you keep seeing small points of scarlet against the litter. Walk over and you find a neat, rather small brittlegill with a bright red cap, a white stipe like a stick of chalk and gills so pale they look bleached. Nothing about it is robust: knock the cap edge and a chip breaks off cleanly instead of bending. This is one of the commonest red-capped brittlegills of European beechwoods, often appearing in loose troops along a bank or in the hollows between roots, and getting to a confident name is mostly a matter of reading colour, texture, spore print and, above all, the tree overhead.

The Setting

Habitat here is close to a diagnostic character. The species is an ectomycorrhizal partner of beech and effectively nothing else, so you should be standing under beech, ideally in a mature stand on chalk or clay with a deep litter layer and thin ground vegetation. It appears from midsummer into autumn, sometimes rather early relative to other brittlegills, and it fruits reliably enough that a good beech slope will produce it year after year. If you are among conifers or in a bog, you are looking at something else, no matter how similar the cap looks.

Reading the Cap

The cap is small to medium, three to seven centimetres across, convex at first and expanding to flat with a shallow central depression. Colour is a bright scarlet to cherry or blood-red, evenly laid on when fresh. Look for fading: after rain or with age, irregular pale patches appear, washing through pink to cream or almost white, often leaving the centre reddest. That patchy bleaching is characteristic of the group and gives many collections a two-tone look.

Surface texture is smooth and matt to slightly shining when moist, never scaly or hairy. Now test the cuticle. Take the edge of the skin between thumbnail and finger and peel: in this species it lifts only about a quarter to a third of the way toward the centre before tearing. That limited peel is a real character and worth doing on every red brittlegill you meet.

The margin is smooth in young specimens and only becomes faintly grooved or lightly tuberculate in old, over-expanded ones. A strongly grooved margin on a young cap points elsewhere.

The Gills

Gills are white to the very palest cream, moderately crowded, adnexed to almost free, and fairly broad. They are notably brittle: draw a fingertip across them and they shatter rather than flexing, which is the classic brittlegill test. Edges are even and stay pale, without the finely serrated edge some relatives show under a lens. Some gills fork near the stipe. In good light they can show a faint bluish-white sheen. Damaged gills do not yellow, redden or grey to any significant degree.

Stipe, Base and Flesh

The stipe is three to six centimetres tall and one to two thick, cylindrical or slightly clubbed toward the base, pure white, finely wrinkled lengthwise, with no ring and no volva. Fresh specimens are firm; older ones become chalky and develop internal cavities, so slice one lengthwise to see the pithy or hollowed core.

The flesh is white and thick over the disc. Its texture is the important thing: it is granular rather than fibrous, built from rounded cells, so a stipe snaps across cleanly like chalk rather than pulling apart in strings. That snap distinguishes the whole genus and its close allies from almost every other gilled fungus. On cutting, the flesh remains white or greys very slightly and slowly; there is no dramatic colour change, no latex and no blueing. Fresh material has a faint sweetish smell that becomes heavier and more cloying as the fruit body ages.

Taking a Spore Print

Spore colour matters a great deal in this genus, so make a thick print. Cut the cap off just below the gills, set it gills-down on white paper, cover it with a bowl, and leave it four to eight hours or overnight. Then scrape the deposit into a compact heap with a blade before judging it against the light, because thin dustings always read too pale. Here the deposit is white to the palest cream, at the very lightest end of the genus scale. Under a microscope the spores are broadly elliptic, roughly seven to nine by six to seven micrometres, ornamented with warts joined by fine lines into a partial network, and the ornamentation stains blue-grey in iodine. A drop of iron salts on the stipe surface produces a pale salmon-pink flush, the usual reaction for this group and a useful confirmation.

Separating the Look-alikes

The Sickener, Russula emetica. The classic confusion. It is a larger fungus with a glossier, more brilliant blood-red cap whose cuticle peels almost completely, and its stipe is proportionally longer. Habitat is the clean separator: it grows in damp conifer woods and among Sphagnum in bogs, not under beech.

Fragile Brittlegill, Russula fragilis. Found in mixed woodland, with a cap that mixes purplish-red, violet and often a dark, almost blackish centre. Under a hand lens its gill edges are finely toothed or serrated, which the Beechwood Sickener never shows.

Birch Brittlegill, Russula betularum. A pale, washed-out pink to nearly white cap, slighter in build, and associated with birch, often on damp ground.

Bloody Brittlegill, Russula sanguinea. Grows with pine, has a stipe flushed pink or rose rather than pure white, and drops a deeper cream print.

Rosy Brittlegill, Russula rosea. Firm and hard-fleshed, matt rose-red, with cream gills, a stipe often tinged pink, and it does not bleach in the same patchy way.

Golden Brittlegill, Russula aurea. Yellow gills, a yellow-flushed stipe base and an orange-red cap, so the pale gills and white stipe here rule it out immediately.

Waxcaps and small red Mycena species. Both have flexible, non-granular flesh that bends rather than snapping. The chalk-snap test dismisses them at once.

The Working Combination

A small scarlet cap that bleaches in irregular pale patches, a cuticle peeling only at the margin, brittle white gills with even edges, a chalk-white granular stipe, a white to palest cream spore deposit, and beech overhead. Assemble all six and the identification is sound.