Flaming Scalycap Identification Guide

The log you are standing over

Flaming Scalycap belongs to cool, damp conifer forest: boreal woodland, or montane spruce and fir at elevation, in the sort of stand where the fallen trunks are cushioned in moss and the ground stays wet through the summer. The setting is a well-rotted conifer log or stump, often one that has lost its bark and softened enough to take a thumbprint.

You see the colour long before you see the shape. A burst of pure golden, almost sulphur-yellow caps on the flank or the sawn end of a mossy log is brighter than anything else likely to be on rotting conifer wood, and it reads clearly from twenty paces in shade. Fruit bodies appear singly, in pairs or in small clusters of three to five, usually growing straight out of the side of the wood so the stipes curve upward toward the light.

Reading the cap

The cap is 2 to 8 cm across, hemispherical when young, then convex, broadly convex and finally nearly flat. The ground colour is bright golden yellow to lemon or tawny-gold, and the surface beneath the ornamentation is slightly tacky in wet weather and dry in fine weather.

The ornamentation is what you came for. The cap is covered in conspicuous, upturned, pointed scales of the same sulphur-yellow, arranged in rough concentric rings and crowded most densely over the centre. These are dry, erect and spiky rather than flattened patches, and they stand up enough to catch side light and cast small shadows. When the fruit body is young the margin also carries hanging fragments of the yellow partial veil.

Note that both the ground colour and the scales are yellow. A great deal of the separation from related species turns on that single point: many relatives have yellow ground with brown or tawny scales, which makes them look two-toned rather than uniformly gold.

Gills, stipe and flesh

The gills are adnate, sometimes shallowly notched or running down the stipe as a fine tooth, crowded and narrow. In young fruit bodies they are a pale sulphur-yellow that matches the cap. As the spores ripen they dull first to olive-yellow and then to a clear rusty cinnamon-brown. That progression matters: a specimen whose gills are still pure yellow is simply too young to be read confidently, and you should look for an older one on the same log.

The stipe is 3 to 8 cm long and 4 to 10 mm thick, roughly equal or slightly tapering downward, and usually curved where it leaves the wood. It is yellow throughout. Below a fibrillose ring zone it is densely clothed in the same recurved yellow scales, so it looks shaggy from the ring down; above the ring it is smoother and paler. The ring itself is not a firm membranous skirt but a woolly zone where the veil tore, and because it sits in the fall line of the gills it usually collects rusty spores and darkens to brown, which makes it easier to see with age.

At the base the fruit body attaches directly to the wood, sometimes with a small pad of yellowish-white mycelium binding the softened fibres. There is no bulb, no volva and no sheath.

Cut the fruit body lengthwise. The flesh is yellow throughout, in cap and stipe alike, which is a useful confirmation because several yellow-capped imitators are white inside. It is firm in the cap and more fibrous in the stipe, and it shows no dramatic colour change on cutting, though the base may darken to brownish with age. The odour is mild and vaguely fungal.

Taking a spore print

This is the test that resolves the whole yellow-mushroom-on-wood problem in one step. Cut the stipe flush with the gills, set the cap gill-side down on white paper, cover it with a cup and leave it three to six hours. Use white paper rather than black, since a rusty deposit reads poorly against a dark background.

The print is rusty brown to cinnamon-brown. Under the microscope the spores are small, smooth and ellipsoid, roughly 3.5 to 5 by 2.5 to 3.5 micrometres, pale rusty in water and lacking an obvious germ pore. Golden, thick-walled cystidia are scattered across the gill faces.

Substrate, season and range

Flaming Scalycap is a decomposer of dead conifer wood, working on spruce, fir, pine and hemlock in the form of fallen logs, stumps, large branches and buried wood. Occasionally it behaves as a weak parasite at wounds on living trunks, but the typical substrate is well-rotted debris on a damp forest floor. It does not fruit from soil, and finding an apparently terrestrial specimen usually means there is a buried piece of conifer underneath.

Its distribution is boreal and montane: northern and mountainous Europe, northern Asia, and northern North America extending south along the mountain chains. Fruiting runs from late summer through autumn, peaking with the cool wet weather that follows the first substantial rains.

Separating it from its look-alikes

Pholiota squarrosa is the classic mix-up. It is larger, distinctly dry, and its ground colour is straw to buff with darker brown or tawny recurved scales, so it reads two-toned rather than uniformly gold. It grows in big dense tufts at the base of trunks, often on broadleaved trees, and its gills pass through a greenish-tinged phase before turning rusty.

Pholiota aurivella and Pholiota limonella are golden-orange but conspicuously viscid, and their scales are flattened, gelatinised patches pressed onto the surface rather than dry erect spines. They typically grow high on broadleaved trunks in wounds and broken limbs, and their stipes are far less shaggy.

Gymnopilus species also drop a rusty print, but their caps carry fine appressed fibrils rather than bold recurved scales, the colour tends toward orange-tawny, and they usually form large clusters on stumps.

Tricholomopsis rutilans has a yellow ground overlaid with wine-red to purple scales, keeps yellow gills at maturity, and drops a white spore print.

Cyptotrama asprata is a small golden mushroom with erect pointed scales, but its gills are white and stay white, and its spore print is white.

Hypholoma fasciculare shares the sulphur colour but its cap is entirely smooth with no scales at all, its gills go greenish, and its print is purple-brown.

Phaeolepiota aurea is golden and granular-powdery with a large membranous ring, and it grows from soil rather than wood.