Parasola auricoma
Parasola auricoma
Also called goldenhair inkcap
A delicate pleated inkcap of mulch and path edges whose young cap carries scattered stiff brown hairs, visible with a hand lens, that give the species its golden-haired name.
Overview
Parasola is a small genus split from Coprinus for the pleated, umbrella-like inkcaps. Their caps are thin to the point of transparency and folded into deep radial pleats that follow the gills, so that an expanded fruit body looks like a tiny collapsed parasol. Unlike the true inkcaps they barely deliquesce; instead the cap simply withers and curls away by mid-morning.
Parasola auricoma is the hairy member of the group. Scattered across the surface of the young cap, especially over the disc, are thick-walled brown setae, stiff bristle-like hairs that under a lens look like fine dark whiskers standing proud of the pleats. The epithet auricoma means golden-haired and refers directly to them. No other common Parasola has them.
It is a fungus of disturbed, humus-rich, often man-made ground, and has become far more frequent with the spread of bark and woodchip mulch in gardens, car parks and municipal planting beds. Troops appear overnight after rain and are usually gone by afternoon.
How to identify it
Cap
1-4 cm across when expanded, at first ovoid to ellipsoid and only 1-2 cm tall, then opening quickly to convex and finally flat or with an uplifted margin. The centre is date-brown to reddish-brown, the rest grey to greyish-brown, and the whole surface is folded into deep radial pleats or grooves running from the margin almost to the disc. Scattered over the young cap, and best seen with a hand lens against the light, are short, stiff, dark brown hairs.
Gills
Free from the stipe, narrow, moderately spaced, greyish-white at first, then grey and finally black. They do not dissolve into copious ink; the cap collapses and shrivels instead.
Stipe
4-10 cm long and 1-3 mm thick, white to very pale cream, hollow, smooth to minutely downy, very fragile and easily snapped. There is no ring and the base is only slightly swollen, without a bulb or volva.
Flesh & spore print
The flesh is exceedingly thin, membranous, greyish, without significant odour. The spore print is black. Microscopically the setae on the cap surface confirm the identification, and the spores are smooth, dark and lens-shaped in one view with a central germ pore.
Where and when it grows
It favours rich, disturbed, humus-laden ground: bark and woodchip mulch in beds and borders, the edges of gravel paths, lawns with buried woody debris, compost-enriched soil, roadside plantings and the litter under hedges. It is common in gardens, parks and urban green space, and much less frequent in undisturbed woodland.
The species is widespread across Europe and North America and is reported from temperate regions worldwide, spreading readily with landscaping materials. Fruiting begins in late spring and continues into autumn, with flushes appearing overnight after warm rain and troops of a dozen or more fruit bodies emerging together, each lasting only a matter of hours.
Ecological role
Parasola auricoma is a saprotroph that decomposes small woody fragments, buried twigs and humus in the top layer of soil and mulch. It is a rapid coloniser of freshly laid organic material and is often among the first agarics to fruit on a new mulch bed, contributing to the early breakdown of bark and chipped wood.
The extreme ephemerality of the fruit bodies is a viable strategy because the pleated cap can be built from very little tissue and expanded almost instantly, so the fungus can respond to a single night of rain, release its spores at dawn and be finished before the surface dries. The stiff cap setae are thought to help support the paper-thin tissue as it expands.
Similar species
Parasola plicatilis, the Pleated Inkcap, is almost identical in shape but has a completely smooth cap without setae, tends to greyer colours with a small ochre disc, and is more typically found in short grass and lawns. Parasola leiocephala is another smooth-capped species, browner and more often in woodland litter.
Coprinellus disseminatus fruits in swarms of hundreds on and around stumps, and its tiny caps are pale grey-buff, finely hairy all over rather than bristled, and grooved but not so deeply pleated. Small Coprinellus species such as C. micaceus differ in having glistening granular veil remnants on the cap and in deliquescing properly into ink.