Golden Bootleg Identification Guide

The first sighting

Golden Bootleg is one of the few fungi that can be identified from a moving car. It is large, it is a saturated golden-tawny colour, and it grows in troops on open, disturbed, nutrient-rich ground - road verges, the bases of hedges, nettle beds, the edges of farm tracks, river banks, spoil from ditching work, and the scruffy margin where a wood meets a field. A good colony can produce dozens of fruitbodies in a band several metres long, and against dark nettle foliage they look like a row of golden lamps.

Get close and the second impression is texture. The whole fungus - cap, stem below the ring, and the outer face of the ring itself - is coated in a dry, fine, granular powder, as if it had been dusted heavily with turmeric or fine sand. Rub a cap with a fingertip and the granules come away, leaving a smoother, slightly paler surface beneath and a golden smear on your skin. That granular coat, on a large mushroom with a big flaring ring, is the species in one sentence.

Reading the cap

The cap ranges from 5 cm to well over 20 cm across in good specimens. It starts strongly convex, almost hemispherical, and expands to broadly convex or flat, usually retaining a low broad umbo. The margin is inrolled for a long time and frequently carries hanging fragments of the veil.

Colour is golden ochre to tawny, warm orange-brown, sometimes deepening to rusty over the centre with age and paling towards the edge. The surface is dry, never viscid, and the granular coating is uniform rather than arranged in discrete raised scales. In heavy rain the granules can wash off patchily, so check several caps in a troop.

Cut a cap in half. The flesh is thick, firm, whitish to pale yellow, and it does not change colour appreciably on exposure. There is a faint odour, slightly sweetish and acidic, which is not a useful diagnostic on its own.

Gills and the crucial colour shift

The gills are crowded, fairly narrow, and adnexed to almost free from the stem. Young fruitbodies have pale cream to pale yellowish gills, and this is exactly what leads people astray, because at that stage the combination of a scaly-looking cap, a big ring and pale gills says Lepiota or parasol.

Watch what happens with age. As spores mature the gills darken steadily through buff and clay to a definite rusty ochre-brown, and older caps show gills that are unmistakably brown. Rusty deposits also collect on the upper face of the ring and on the cap margins of specimens standing beneath others. That progression from pale to rusty is the pivot on which the identification turns.

Stipe, ring and base

The stem is stout and substantial: 8-20 cm long, 1-3 cm thick, often thickening downwards into a swollen base, and firm rather than fibrous-stringy.

The ring is large, membranous, persistent and flaring - it stands out from the stem like a wide skirt or collar, sometimes torn but rarely disappearing. Above the ring the stem is smooth, dry and paler, often nearly cream. Below it, the stem is clothed in the same golden granular powder as the cap, and the upper surface of the ring is usually dusted rusty by fallen spores in mature material. A big flaring ring with granular powder below it and rust-stained upper face is a strong combination.

Dig the base out rather than snapping the stem. There is no volva and no sac, just a slightly bulbous base bound into rich soil, often among nettle roots, with white cords of mycelium running off into the litter.

Taking and reading the spore print

This step is not optional, because it is what separates the species from the white-spored scaly mushrooms it resembles.

Cut a mature cap free, set it gills-down on white paper, cover it with a bowl to keep it from drying, and leave it four to twelve hours. Because the cap is large you will get a heavy deposit, so allow room. The print is ochre-brown to rusty ochre - clearly coloured, never white or cream. Scrape it into a thick pad before judging.

Under a microscope the spores are elongate-elliptical, faintly roughened to almost smooth, and about 10-14 x 5-6 micrometres. A big ringed mushroom with a granular cap and a rusty print is Golden Bootleg; a big ringed mushroom with a scaly cap and a white print is a parasol or a Lepiota relative.

Habitat, season and behaviour

Golden Bootleg is a saprotroph of rich, disturbed soil rather than a woodland root partner. It favours nitrogen-enriched ground: nettle beds, manured verges, spoil heaps, alder and willow banks, forestry track edges, and gardens on good soil. It is often found close to stands of nettle, elder or hogweed, all indicators of the same enriched conditions.

It fruits from late summer into mid autumn. Its behaviour is famously erratic - a site can produce an enormous flush one year and nothing for several years afterwards, then reappear. When it does fruit it usually does so in numbers, in arcs, lines or dense troops, reflecting mycelium spreading through a band of rich soil.

Separating the look-alikes

• Cystoderma species, especially Cystoderma amianthinum, have the same dry granular coating and a ring, but they are small, rarely above 5 cm, ochre-yellow, and they drop a white spore print. Size and print colour separate them at once.
• Macrolepiota and Chlorophyllum species (parasols) are large and ringed but have a fibrous cap breaking into discrete raised scales over a paler ground, gills that stay white or cream, a movable ring, and a white print. They also usually have a patterned or snakeskin-like stem.
• Gymnopilus junonius is large, tawny and rusty-spored, but it grows in dense tufts on wood or from buried roots, has a fibrillose to finely scaly rather than granular cap, and its gills start yellow rather than cream.
• Pholiota species are rusty-spored too, but they fruit on wood, are often viscid, and carry upturned scales rather than a dusting of granules.
• Cortinarius caperatus has a wrinkled, silky, ochre cap and a ring, but the cap surface is not granular and the young fruitbody shows cobwebby veil threads.
• Armillaria species grow on wood, have a ring, and drop a white print.

Field checklist

Large golden-tawny mushroom in a troop on rich disturbed open ground; whole surface dusted with dry granular powder; big flaring persistent ring, rusty on its upper face; gills cream then rusty ochre; firm pale unchanging flesh; no volva; rusty ochre spore print; late summer to autumn. If the print comes up white, you have something else.