Flame Mycena

Mycena strobilinoides is the brightest of the North American bonnets, a flame-orange to scarlet mushroom that stands out sharply against the brown needle duff of montane conifer forest. Where many small red Mycena fade quickly, this species holds a saturated orange-red across most of its life, and troops of it can dot a forest floor like sparks.

The colour is carried throughout the fruit body. The cap is scarlet to orange-red, the gills are pale orange to yellow-orange with distinctly red to red-orange edges, and the stipe is orange-yellow with a base surrounded by a conspicuous ring of stiff orange-red fibrils. That basal fibril tuft is one of the more useful confirming characters.

It is primarily a western North American species, abundant in the Pacific Northwest, the Sierra Nevada, the Rockies and the coastal ranges, where it is one of the signature small fungi of both the autumn rains and the spring snowmelt zone at higher elevations.

Cap

The cap is 5–25 mm across, conical to bell-shaped, expanding to broadly convex with a low umbo. The surface is smooth, moist and translucent-striate towards the margin, coloured bright scarlet, flame-orange or orange-red, usually deepest at the centre and shading to orange or yellow-orange at the margin. It fades only slowly compared with other red bonnets.

Gills

Gills are adnate to narrowly adnexed, fairly distant, and pale yellow to orange on the faces. The gill edges are distinctly darker — red to orange-red — forming a fine coloured line, best seen with a hand lens.

Stipe

The stipe is 2–7 cm tall and 1–2 mm thick, hollow, smooth to minutely pruinose, coloured yellow-orange to orange, often paler at the apex. The base is surrounded by a conspicuous tuft or ring of coarse, stiff orange to orange-red fibrils that trap needles and duff fragments.

Flesh & spore print

The flesh is very thin and orange-tinged, with no distinctive smell. The spore print is white; spores are smooth, ellipsoid and amyloid.

Flame Mycena fruits on conifer duff — the packed layer of fallen needles, cone scales and fine twigs beneath pine, fir, spruce and hemlock. It favours montane and coastal coniferous forest, often appearing on moss-covered duff, along shaded trail edges and in the litter around downed logs.

The species is characteristic of western North America, from Alaska and British Columbia south through Washington, Oregon and California into the Rocky Mountain states, with scattered records elsewhere in the coniferous Northern Hemisphere. It fruits in the autumn rains at lower elevations and again in spring near receding snowbanks at higher altitude, making it one of the species associated with the snowbank fungal flora.

Mycena strobilinoides is a saprotroph of conifer litter, decomposing needles, cone scales and fine woody fragments in the duff layer. Its mycelium spreads horizontally through this loose organic mat, and the orange fibrils at the stipe base are the visible expression of that mycelium binding substrate around the fruit body.

By fruiting both in autumn and at snowmelt, it exploits the two reliably wet windows in a western montane climate that is otherwise dry for long stretches. Populations can be locally abundant, with dozens of fruit bodies scattered across a small area of duff, each releasing white spores over a few days before collapsing.

Mycena acicula is smaller with a hemispherical orange cap and a clear yellow stipe, and grows on fallen twigs and woody debris rather than in conifer duff; it lacks the orange basal fibril tuft. Mycena adonis has a pinker, coral-scarlet cap that fades quickly and a whitish stipe, and favours moss and grass.

Mycena aurantiomarginata shares orange colouring but has a dull olive-brown cap with only the gill edges bright orange. Small orange species of Rickenella and Xeromphalina are separated by strongly decurrent gills running down the stem, whereas M. strobilinoides has adnate to adnexed gills and a classic conical bonnet profile.