The Deceiver Identification Guide

The First Impression

The Deceiver earns its name honestly: it is so variable in colour, size and shape that beginners identify it three separate times as three different species before the penny drops. The trick is to stop reading the cap and start reading the gills, which are far more constant than anything else about the fungus.

The setting is almost anywhere with trees. Scattered troops appear along woodland path edges, on mossy banks, in birch scrub, under oak and beech, in conifer plantations, on heathland with scattered birch, and on the disturbed ground of forest tracks. Fruitbodies are small and dull, they come up in numbers rather than singly, and they are frequently the most abundant mushroom in a wood on a quiet autumn day.

Your first impression should be: small tawny mushroom, thin fibrous stem, and — when you tip it — surprisingly thick, widely spaced, pink-toned gills that look almost waxy.

Reading the Cap

Caps run from one and a half to five centimetres. Young caps are convex, expanding to flat and often finally becoming irregularly wavy, uplifted or shallowly depressed at the centre, so a mature troop contains an odd assortment of silhouettes.

Colour is where the deception happens. Fresh, wet fruitbodies are a warm brick, tawny-orange or pinkish-brown. The cap is strongly hygrophanous, so as it dries it pales dramatically and unevenly to dull buff, pinkish-cream or nearly whitish, usually fading from the centre outward and often leaving a two-toned or streaky appearance. Two caps from the same troop, one in sun and one in shade, can look nothing alike.

Look closely at the surface with a lens: it is not smooth but finely scurfy, granular or minutely scaly, especially toward the centre, giving a slightly roughened matt texture. When wet, the margin is faintly striate and often becomes crenate or split with age.

Reading the Gills

This is the section that matters. Turn the cap over and check four things.

First, spacing: the gills are distinctly distant — widely spaced, with clear gaps between them, so you can count them fairly easily around the cap. Second, thickness: they are notably thick and rather rubbery for such a small mushroom, with a soft, slightly waxy feel when rubbed between finger and thumb, quite unlike the papery gills of similar-sized woodland mushrooms. Third, colour: a distinctive flesh-pink, salmon-pink or pinkish-buff, holding that tone even as the cap fades. Fourth, attachment: adnate to slightly decurrent, running a short way down the stipe rather than being free.

In mature fruitbodies you will often see the gill faces dusted with a fine white bloom. That bloom is the fungus's own spore deposit sitting on the pink gills, and it is a helpful clue to the spore colour before you have even taken a print.

Stipe, Base and Flesh

The stipe is slender, three to ten centimetres tall and only a few millimetres thick, cylindrical or slightly flattened, and often curved or twisted. Its texture is the second constant feature: it is tough and fibrous, with coarse longitudinal fibrils running its length that make it look wiry and slightly twisted. Try to snap it and it tends to shred lengthwise rather than break cleanly.

Colour follows the cap — tawny to reddish-brown, paler when dry — and the extreme base is usually clothed in a conspicuous cottony white mycelial down that clings to soil and moss. There is no ring and no volva.

The flesh is thin, concolorous with the surface, watery when wet, and shows no colour change of any kind when cut or bruised. There is no distinctive smell and no latex.

Taking a Spore Print

Take a print. With pinkish gills, the print is what stops a beginner walking away with a completely wrong genus.

Cut the cap free, set it gills-down on black paper or glass, cover it, and leave it four to eight hours. The deposit is white — pure white, not pink, not brown. A white print from pink gills is a strong signal in favour of this group.

Under a microscope the spores clinch it: they are globose to broadly ellipsoid and conspicuously covered in coarse spines or echinulations, standing out around the outline like a tiny mace-head. Smooth spores, or angular spores, take you elsewhere immediately.

Substrate and Season

The fungus is mycorrhizal, forming root partnerships with a broad range of trees — birch, oak, beech, hazel, pine and spruce among them — which explains both its abundance and its willingness to appear in young plantations and scrub as readily as in old woodland. It favours mineral soil that is not too rich, and it is characteristically abundant on the bare compacted edges of paths, on mossy banks and on the sides of ditches where soil has been exposed.

Fruiting runs from midsummer to late autumn, sometimes continuing into early winter in mild spells, with troops appearing in the same spots year after year. It fruits in quantity even in relatively dry seasons when larger fungi fail.

Separating It From Look-alikes

Within the genus, work on size, texture and colour.

The Scurfy Deceiver is larger and taller overall, with a more strongly and coarsely scaly cap, a distinctly longer and more fibrous stipe, and a preference for damp acid ground — boggy birch woodland, wet heath and Sphagnum margins. The two overlap and intermediate collections are genuinely difficult.

The Bicoloured Deceiver looks very similar from above, but tear open the stipe base and pull away the attached soil: its basal mycelium is a clear lilac to violet, and the young gills usually carry a faint lilac wash. That base colour is the whole test.

The Amethyst Deceiver is unmistakable when fresh — deep violet throughout, cap, gills and stipe — but as it dries it fades to a washed-out pale lilac-buff and can then look alarmingly like the present species. Check the gills for surviving violet tones and check the stipe base.

The Twisted Deceiver is much smaller, with very few, very thick gills, a short stipe and a tendency to appear on bare wet soil and clay banks.

Outside the genus, the important separation is from the pinkgills, which also have pink-toned gills. They differ in giving a distinctly pink to salmon-brown spore print and, microscopically, in having angular spores with flat facets. A print alone resolves it. Waxcaps have thicker, more waxy, more brightly coloured gills and smooth greasy caps in grassland rather than woodland, and the small brown toughshanks have thin, crowded, pallid gills and smooth caps.