Pholiotina rugosa

Pholiotina rugosa is a small brown agaric of the Bolbitiaceae, closely allied to the conecaps but set apart by a well-formed membranous ring on the stipe. It has been catalogued under several names, including Conocybe rugosa and Conocybe filaris, and most modern authorities regard Pholiotina filaris as the same fungus.

The genus Pholiotina gathers the ringed relatives of Conocybe, sharing their rusty-brown spore print, thin flesh and fragile build, but adding a persistent annulus formed from a partial veil. In this species the ring often sits some way down the stipe and can slide loosely once it detaches.

It is a fungus of mulched garden beds, wood chip paths and disturbed grassy ground, appearing through the warmer months and, like most of its relatives, lasting only a day or two.

Cap

The cap is 1 to 3 cm across, conical to convex and then broadly bell-shaped, often with a low umbo. Moist caps are tawny brown, cinnamon or reddish-ochre and fade markedly on drying to dull ochre or pale buff. A distinctive feature is the finely wrinkled or radially rugulose disc, particularly noticeable as the cap dries, and the margin may be faintly striate when wet.

Gills

Gills are adnate to adnexed, close, fairly narrow, pale buff or clay at first and turning warm rusty cinnamon as the spores ripen. The colour deepens evenly rather than in mottled patches, and the edges are finely paler.

Stipe

The stipe is slender, 2 to 6 cm long by 1 to 3 mm thick, equal or slightly thickened at the base, hollow and brittle, whitish to pale brown and darkening downward. Its most important feature is a distinct membranous ring, usually placed at or below mid-height, whitish and often becoming dusted rusty from falling spores; the ring can detach and slide loosely on the stipe. Above the ring the stipe is often finely pruinose, below it faintly fibrillose or lined. There is no volva.

Flesh and spore print

The flesh is thin, pallid brown and unchanging on cutting. The spore print is rusty brown to cinnamon. Microscopically the spores are smooth, ellipsoid and have a germ pore, and the gill-edge cystidia are not of the skittle-shaped type typical of true Conocybe, a technical point that supports the placement in Pholiotina.

This species grows on wood chip mulch, bark beds, decaying sawdust, garden borders enriched with compost, and in mossy or grassy ground including lawns and path edges. It is very much a fungus of managed and disturbed ground, and mulched municipal plantings suit it particularly well.

Fruiting occurs from late spring through summer into autumn, usually in scattered small troops that follow rain. The species is widespread across Europe and North America and occurs in temperate regions generally; wherever landscaping wood chip is spread it tends to turn up sooner or later.

Pholiotina rugosa is saprotrophic, decomposing woody mulch, bark fragments, sawdust and the humus-rich layer of disturbed garden soil. It forms no mycorrhizal partnership with plants and has no parasitic role.

Its ecology is that of a rapid coloniser of freshly applied organic material. Mycelium spreads through a mulch layer over weeks, and once moisture and warmth coincide it throws up delicate short-lived fruit bodies. The membranous veil protects the developing gills until expansion, then tears to leave the ring, and the rusty spores are dispersed on air currents to new mulch and disturbed soil elsewhere.

The most obvious comparison is with true conecaps such as Conocybe tenera and Conocybe apala, which share size, colour, fragility and the rusty spore print but have completely bare, unringed stipes. The presence of a movable membranous ring is the immediate separator.

Pholiotina aporos and other ringed Pholiotina species are very similar and generally require microscopy, with spore dimensions and germ pore development being the practical characters. Galerina marginata on wood is bigger, with a browner, smoother, more hygrophanous cap, a tougher fibrous ringed stipe and a habit of growing directly on stumps and logs rather than loose mulch. Agrocybe species on mulch are much fleshier and paler, with a broader flat cap and a brown rather than bright rust print, and Tubaria furfuracea has a rusty-brown cap with pale veil scurf at the margin but no true ring.