Beautiful Bonnet Identification Guide

The First Impression

This is a fungus you notice by its stem, not its cap. Working along a mossy beech log in a damp wood, you catch a glint of bright yellow among the leaf litter, and following it down you find a small, delicate bonnet perched on a wire-thin stipe that looks lacquered. The cap is modest, honey-brown to tan and finely grooved, but the stipe is a clean chrome to golden yellow and reflects light like polished plastic. Fruit bodies are scattered or in small loose tufts of two to six, always attached to dead broadleaved wood, and they are usually at knee height or lower, so the find is generally made while bending or kneeling.

The Setting

Expect old deciduous woodland with plenty of fallen timber, especially beech. Fallen trunks, cut stumps, thick branches lying in the litter and half-buried limb wood are all suitable, and the fungus favours bark-covered or freshly exposed surfaces rather than deeply rotted crumbly wood. Oak and hornbeam also serve. The fruiting season is long, running from late spring through the summer and into autumn, with the best flushes after prolonged damp. Because it grows on wood rather than soil, always confirm the attachment by teasing the base free with a knife point; small pieces of buried wood beneath litter catch people out regularly.

Reading the Cap

The cap is one to two and a half centimetres wide, conical or bell-shaped at first and expanding to a broad bell or a flattish shape with a low central umbo. Colour ranges from pale honey and ochre-tan to a warm reddish-brown, always darker over the disc and paler toward the margin, and the whole cap is hygrophanous, so a specimen that dried on a sunny afternoon looks far lighter than the same specimen after rain. When moist, translucent striations run from the margin nearly to the centre, marking the position of the gills beneath. The surface is dry to slightly greasy, never slimy, and the margin is even rather than toothed or scalloped.

The Gills

Gills are white to pale grey, sometimes with a very faint pinkish or cream cast in age. They are moderately spaced, fairly broad, and attached adnately, frequently with a short decurrent tooth running a little way down the stipe apex. The edges stay white and even. Short gills alternate with the full-length ones. Nothing on the underside is yellow, which matters: the yellow pigment in this species is confined to the stipe.

The Stipe and Base

This is the decisive part of the fungus. The stipe is three to eight centimetres long and only one to two millimetres thick, cylindrical, hollow, smooth and conspicuously shiny, as though varnished. The colour is bright chrome-yellow to golden over most of its length, often becoming paler or almost whitish right at the apex and sometimes deepening toward the base. Crucially, it is dry, not viscid: run it between finger and thumb and nothing sticks. At the very base sits a cuff of coarse, stiff white hairs, sometimes described as bristly or strigose, which anchor the stipe to the wood and trap fragments of bark and moss. Ease the fungus off carefully so this hairy base survives intact, because it is a genuine identification character rather than incidental debris.

Flesh, Colour Change and Odour

The flesh is very thin, pallid to faintly yellowish in the stipe, and it does not change colour when broken. There is no latex of any kind: a cut stipe stays dry. Crush a cap and stipe together between the fingers and a distinctly nitrous, sharp, slightly ammoniacal smell develops after a few seconds. That odour, when it is present, supports the identification, though it varies in strength with weather and age and should never be used alone.

Taking a Spore Print

A print from a fungus this small takes patience. Cut two or three caps free at the very top of the stipe, arrange them gills-down on black glass or dark card, cover them with a small box to keep the humidity up, and leave them overnight. The deposit is white, thin and easily missed against pale paper, which is why dark backing is worth the trouble. Under the microscope the spores are elliptic, roughly seven to nine by four to five micrometres, smooth, and they stain blue-grey in iodine, which is normal for the genus. The gill-edge cells are club-shaped and covered in short rod-like outgrowths, a detail that confirms the species for anyone working with a scope.

Distinguishing the Close Relatives

Yellowleg Bonnet, Mycena epipterygia. The commonest source of error, because it too has a yellow stipe. The difference is texture: its stipe is distinctly slimy or sticky and its cap carries an elastic, detachable skin that can be peeled off in one rubbery sheet. It also favours conifer needle litter, heath and grassy places rather than beech logs. A dry polished stipe rules it out.

Clustered Bonnet, Mycena inclinata. Grows in dense tufts on oak stumps, has a cap margin that is scalloped or minutely toothed, and its stipe is white above and rusty-orange to red-brown below rather than clear yellow. It is also a noticeably larger and more robust fungus.

Saffrondrop Bonnet, Mycena crocata. Also on beech, but the stipe is pallid and cutting it releases a bright orange latex that stains fingers immediately. Any latex rules out the Beautiful Bonnet.

Angel's Bonnet, Mycena arcangeliana. Olive-grey to greenish-grey cap with a greyish-yellow stipe rather than a bright chrome one, and it develops a strong iodine-like smell rather than a nitrous one.

Common Bonnet, Mycena galericulata. Larger, grey to grey-brown throughout with a grey-brown stipe and gills that flush pinkish. No yellow anywhere.

The Working Combination

Honey to reddish-brown striate cap, white to grey adnate gills with a small decurrent tooth, a dry polished chrome-yellow stipe, a base fringed with stiff white hairs, dead beech wood underneath, and a white spore deposit. Assemble those six and the identification holds.