Tiger's Eye Identification Guide

The Setting You Are Standing In

Tiger's Eye is a path fungus. You find it standing on bare, sandy, acidic ground: the trodden edge of a forest ride, a heathland track, the compacted soil of an old campfire ring, a firebreak in a pine plantation, or a bank where the turf has worn away. It likes places that are poor, gritty and open, often with scattered heather, wavy hair-grass and moss.

The first impression is odd enough to be memorable. From above it looks like a small brown funnel, or a shallow wooden wine glass abandoned in the sand — 2 to 5 cm across, standing on a short central stalk, thin and dry and faintly velvety. Often several grow within a metre of one another, and neighbouring caps may fuse into an irregular double or triple funnel. Nothing about it looks fleshy; the whole fruitbody has the air of stiff card or thin leather, and last year's weathered discs sometimes persist alongside fresh ones.

Reading the Cap

The cap is circular to broadly funnel-shaped, flat at first and then depressed in the centre, with a thin margin that is often wavy, lobed or split. It is rarely thicker than a couple of millimetres.

The defining feature is the banding. Concentric zones run outward from the stalk in alternating tones — cinnamon, rust, tawny ochre, greyish-brown, sometimes with a paler cream or straw-coloured band at the growing edge. The rings are broad and soft-edged rather than sharp lines, and in strong light they give exactly the effect the common name suggests. Weathered specimens fade toward uniform grey-brown, so read the banding on fresh material near the margin, where the newest growth keeps its colour.

The surface texture changes with age. Young caps are finely velvety or minutely fibrillose, almost suede-like under a fingertip; older ones wear smooth and slightly silky, especially at the centre. It is always dry — never sticky, never viscid, even in rain.

The Spore-bearing Surface

Turn it over, and the identification narrows sharply. The underside is not gilled but porous. The pores are small and angular, roughly 2 to 4 per millimetre, arranged in a thin tube layer no more than 1 to 3 mm deep, and coloured cinnamon to rusty brown, sometimes with a paler greyish bloom when very fresh.

Critically, the pore surface runs down the stalk — it is decurrent, spreading from the underside of the cap onto the top of the stem for several millimetres before stopping. That combination of a stalked cap and decurrent brown pores on bare soil is close to diagnostic on its own.

Press a fingernail into the pores. They are firm and slightly springy, not soft or spongy, and the tube layer cannot be peeled away from the cap flesh as a separate sheet the way a bolete's tubes can.

Stalk, Flesh and Colour Change

The stalk is central or only slightly off-centre, typically 1 to 4 cm tall and 2 to 6 mm thick, tapering slightly downward, and coloured the same rusty brown as the cap. It is velvety when young, smooth with age, tough throughout, and it flares smoothly into the cap rather than joining it abruptly. At soil level it usually binds sand grains, moss and needle litter into a small anchoring pad of brown mycelium.

Now the flesh. Cut or tear the cap in half. Coltricia perennis is thin-fleshed, leathery to corky, and uniformly rusty brown or cinnamon in section, with a faint darker line sometimes visible between the cap flesh and the tube layer. It does not snap cleanly — it bends, then tears fibrously, like thin hide. There is no colour change on cutting, no bruising reaction, no latex and no gel layer. Dried material becomes rigid and brittle but keeps its colour, which is why old fruitbodies survive on paths for months.

Taking a Spore Print

Tough polypores are less generous with spore deposits than gilled mushrooms, so give the print time. Cut the cap free with a short length of stalk, set it pore-surface-down on a piece of dark card next to a piece of white paper, and cover it with a box or bowl over a damp tissue for 12 to 24 hours. A gentle warmth helps.

The deposit is a pale yellowish-brown to ochre-brown. Against white paper it reads as a distinctly warm buff, which fits with the rusty tone of the tubes themselves. If your print comes out white, you are not looking at Coltricia.

Substrate and Season

This species fruits from soil, not from visible wood — that is the point people most often get wrong, since almost every other stalked polypore they will have met grows on logs. It favours nutrient-poor, sandy or gravelly acidic soils, frequently in conifer woodland and on heaths, and it has a strong association with old burnt ground and hard-packed path surfaces. There is good evidence it associates with tree roots as well as decaying buried woody debris, which fits its consistent appearance in the same spots year after year.

Fresh growth appears from summer into late autumn, but the species epithet is slightly misleading: individual fruitbodies are annual yet extremely persistent, and weathered grey discs from previous seasons can be found through winter and into the following spring. Always base your reading on the freshest, most strongly banded material you can find.

Separating the Look-alikes on Structure

Coltricia cinnamomea — the closest relative. It is smaller and thinner, with a silky-shining rather than velvety cap surface, brighter and more sharply defined rusty-cinnamon zones, a more strongly funnel-shaped outline, and a more slender stalk. It also leans toward hardwood settings and mossy banks rather than open sand.

Onnia tomentosa and relatives — much larger and often clustered, with a tawny woolly-tomentose cap, a stouter and shorter stalk, and a pore surface that is whitish, grey or straw-coloured when fresh rather than rusty. They fruit around conifer roots and stumps.

Picipes badius, Polyporus varius and other stalked wood polypores — these grow on logs, buried wood or stumps, have white to cream pore surfaces, and typically show a stalk that is blackened at least at the base.

Boletes — also stalked with pores, but the whole fruitbody is soft and fleshy, the cap is thick, the tube layer is spongy and peels away cleanly in a mat, and the flesh often changes colour on cutting.

Chanterelles — sometimes mistaken from above because of the funnel shape and terrestrial habit, but the underside bears blunt, forking, wax-like folds rather than distinct pores, and the flesh is thick, pale and fibrous.

Hydnellum and Phellodon species — leathery brown terrestrial fungi of similar habitats, but their undersides carry spines or teeth rather than pores.

A Working Checklist

1. Bare sandy, gravelly or burnt ground, often on a path or heath.
2. Small funnel-shaped cap with concentric cinnamon and ochre zones.
3. Dry, velvety-to-silky cap surface, thin and wavy at the margin.
4. Angular rusty-brown pores running down onto the stalk.
5. Thin, tough, uniformly brown flesh that bends and tears rather than snapping.
6. Yellowish-brown spore deposit.