Spindleshank Identification Guide

The Setting That Gives It Away

Spindleshank is a species you find by looking at tree bases rather than at the ground. Walk an oak wood, a wood-pasture with veteran trees, or an avenue of mature beech in high summer, and check the buttress roots and the collar where trunk meets soil. Spindleshank grows there in dense tufts of five to thirty fruit bodies, the stems twisted together like a bundle of rope, often on the shaded north side of the bole or tucked between root flanges. Two things register immediately. First, the tufts are tough. Where most woodland mushrooms sag and collapse within days, these stand up to weather and stay recognisable for weeks, going leathery and blackened rather than dissolving. Second, they come back. A colonised oak will produce fruit bodies from the same root flange summer after summer, and the blackened remains of last season are often still visible beside this season's fresh caps.

Reading the Cap

Caps are modest, usually 2 to 7 cm across, and rarely uniform within a tuft. They begin convex with an inrolled margin and expand to broadly convex or flat, frequently with a low broad umbo and an irregular, lumpy or bumpy profile as if the surface had been dented. The texture is smooth and dry, sometimes slightly greasy after rain, never truly slimy and never scaly. Colour is a warm reddish-tan to rusty chestnut, deepest at the centre, and the cap is hygrophanous, so it pales as it dries to a buff or leather tone, often blotchily. Old caps develop darker rusty stains and the margin may split. Take colour readings from several caps in the tuft, because a mixture of fresh dark and faded pale caps side by side is normal and can mislead a beginner into thinking two species are present.

The Gills

Turn a cap over and note the spacing first. The gills are distinctly distant, broad, and slightly ventricose, which alone separates this from the crowded-gilled woodland Gymnopus species. Attachment is adnexed to almost free, and the gills often pull away from the stipe as the cap expands, leaving a narrow collar-like gap. Colour is whitish to pale cream when fresh, and this is where the key character develops: with age the faces and edges pick up rusty red-brown spots and blotches, exactly as if the gills had been splashed with rusty water. In mature tufts almost every cap shows the spotting, and it persists in dried material.

The Stipe: the Name Made Literal

This is the character that names the species. The stipe is 4 to 12 cm long, tough and cartilaginous, and swollen through its middle into a spindle or fusiform shape, then tapering downward into a long, tough, rooting extension that runs into the root or the soil beside it. Pull one carefully and you will find that the fused bases of the tuft form a hard blackish mass attached to woody root tissue. The surface is longitudinally grooved and often twisted, so the stem looks fluted, and it is coloured pale near the apex, becoming reddish-brown then almost blackish-brown toward the base. There is no ring and no cortina, and no veil remnants anywhere. Cutting the stipe lengthways shows tough, stringy, whitish flesh becoming brown and often hollow or cavernous with age.

Flesh and Colour Change

Cap flesh is thin, whitish to pale tan, and firm; stipe flesh is much tougher, fibrous and elastic. Cut surfaces do not change colour dramatically, though they slowly brown over time and the base is already brown before you cut it. There is no milk. The odour is faint and unremarkable. The single most useful tactile test is simply to bend a stipe: Spindleshank flexes and resists rather than snapping cleanly, and that toughness separates it from every brittle-stemmed litter mushroom that shares its cap colour.

Taking a Spore Print

Choose a freshly expanded cap that has not yet developed heavy rust spotting, sever it at the top of the stipe and set it gills down on black or dark grey paper under a cover. Give it four to six hours; this is not a heavy shedder. The deposit is white to very pale cream, which is why dark paper matters, and it should be checked against a white sheet as well if you suspect a pinkish tint. A white print in combination with the fusiform grooved stem and distant rust-spotted gills is effectively conclusive.

Substrate, Season and Ecology

Spindleshank lives on the roots and root collars of living broadleaved trees, above all oak, and also beech, hornbeam and sweet chestnut. It is a root-associated fungus of long standing on individual trees, which is why colonies are so faithful to one trunk. Fruiting is early compared with most woodland mushrooms: expect it from late spring or early summer through to autumn, peaking in mid to late summer, and often appearing in dry spells when little else is out. Look at the base of veteran oaks in parkland, on old hedgerow trees, and along the exposed roots of paths cut through oak woods.

Separating the Look-alikes

Russet toughshank, Gymnopus dryophilus, shares the tan hygrophanous cap but is a litter species growing scattered or in small groups on leaves, has crowded pale gills without rust spots, and has a thin, smooth, evenly cylindrical stem with no spindle swelling and no deep root.

Buttercap, Rhodocollybia butyracea, has a smooth greasy cap with a buttery feel, crowded gills, a stem that is club-shaped and grooved but not rooting or twisted into a tuft, and a spore print with a pale pinkish-cream cast rather than pure white.

Honey fungus, Armillaria species, also fruits in tufts at oak bases, but has a ring or veil zone on the stem, paler honey-tan caps with fine dark scales, gills that are attached to slightly decurrent, and black bootlace rhizomorphs under nearby bark.

Rooting shank, Hymenopellis radicata, has a genuine deep pseudorhiza too, but it is solitary rather than tufted, its cap is slimy, wrinkled and grey-brown, and its stipe is long, slender and smooth rather than short, thick, fluted and reddish.

Whiskery deceiver-like species and Megacollybia platyphylla can be dismissed quickly: the latter has a streaky grey-brown cap, very broad gills and white cords radiating from the base rather than a solid rooting spindle.

Field Checklist

Dense tuft at the base of a living oak; tough leathery texture; reddish-tan lumpy hygrophanous cap; distant whitish gills that spot rusty; grooved, twisted, spindle-shaped reddish-brown stipe rooting into wood; no ring; white spore print; summer season. That set does not overlap with anything else you will meet at an oak collar.