Common Conecap Identification Guide

Standing over the find

You usually meet the Common Conecap early in the day. The setting is mown or grazed grass: a suburban lawn still grey with dew, a mossy churchyard, the thatchy edge of a pasture, or a mulched border where wood chips have begun to rot down into soil. What registers first is not colour but proportion. A stalk no thicker than a pencil lead, four to nine centimetres tall, carries a small tan cone barely wider than a fingernail. The whole fruit body trembles in moving air, and if you return in the afternoon the same specimens may have flopped over and dried to a wisp. Conocybe tenera is an ephemeral, and half of recognising it is recognising that fragility.

Reading the cap

Measure first: one to two and a half centimetres across is typical, occasionally three. The outline is conical to bell-shaped and it stays that way, expanding only enough to lift the margin slightly outward, never flattening into a disc the way a Marasmius or a small Agaricus would. Colour is warm ochre-tan to cinnamon-buff, deepest over the centre, and the surface is dry and matt, with a faintly silky sheen in raking light. There is no slime, no gluten, no scaliness.

Watch the cap change while you hold it. Conocybe tenera is strongly hygrophanous: as it loses water it pales from the centre outward, going from tawny cinnamon to a dull straw-cream, so two caps from the same tuft of grass can look like two species. Always record the moist colour, and note whether the margin is finely lined. When damp, the outer third often shows translucent striations that follow the gills beneath; those lines vanish on drying. The margin itself is thin enough to split radially in older specimens.

The spore-bearing surface

Turn the cap over gently, because the gills bruise from handling alone. They are narrow, crowded, thin, and attached to the stipe by a narrow point (adnexed) or nearly free. Young gills are pale clay to pinkish-buff; as spores mature they load up to a rusty cinnamon that eventually dominates the underside. Use a hand lens on the gill edge: in this genus the edge is normally paler than the face, whitish and minutely uneven or fringed. That paleness comes from a fringe of swollen edge cells, and it is one of the more reliable field hints that you are in Conocybe rather than in a small brown Galerina.

Stipe, base and the absent ring

The stipe is the diagnostic organ here. It is one to two millimetres thick, equal from top to bottom, hollow, straight and snappingly brittle, whitish to pale tan and often darkening toward the ground. Under a lens the entire length is finely pruinose, as though frosted, and it usually shows delicate longitudinal striations running the whole way up. The base is slightly swollen into a small bulb, wrapped in whitish mycelial down that binds grass roots, moss and soil crumbs.

Now run a fingertip from cap to base. There is no ring, no ring zone, no fibrillose girdle, and no veil fragments hanging on the cap margin. That absence is not a minor detail; it is the single fastest way to separate this species from the ringed conecaps.

Flesh and colour change

Slice the cap and stipe lengthwise with a blade. The flesh is barely a millimetre thick, pallid to watery ochre, and unchanging. There is no latex, no blueing, no reddening, no slow browning at the cut. The absence of any bruising reaction is itself information: identification has to rest on silhouette, hygrophanous colour, striate margin, pruinose stipe, spore colour and habitat rather than on chemistry.

Taking and reading a spore print

Small ephemeral mushrooms make awkward printers, so work fast. Cut the cap free with a few millimetres of stipe still attached, set it gills-down on a piece of card that is white on one half and black on the other, and cover it with an upturned glass to keep the humidity up. An hour is often enough; two hours is plenty. If the cap collapses first, lay it gills-down on a glass microscope slide instead and scrape the deposit together with a blade tip.

The colour you are looking for is rusty cinnamon to ochre-brown, warm rather than dull, and clearly brown rather than black. Judge it against the white half of the card in daylight, because a thin brown deposit on white looks far paler than the same deposit heaped up. A deposit that comes out chocolate, purple-brown or jet black rules the species out immediately, and so does a white one.

Substrate and season

This is a saprotroph of grassland and disturbed rich ground. It fruits from lawns and mossy turf, from pasture manured by grazing stock, from garden beds, from wood-chip mulch, from rotting straw and heaps of grass clippings, and from potted soil in glasshouses. It never grows directly from standing wood. Fruiting runs from late spring to late autumn wherever there is warmth plus rain, and flushes appear within a day or two of a downpour, then vanish. Distribution is essentially worldwide in temperate regions. Be aware that "Conocybe tenera" in the broad sense is a species complex; many field collections are only ever named to the aggregate without microscopy of the spores and the bowling-pin-shaped edge cells.

Separating it from the look-alikes

Ringed conecaps (Pholiotina rugosa and relatives). Almost identical silhouette, similar tawny cap, similar grassy or mulched ground, but a distinct membranous ring or a ring scar sits on the stipe. Check the stipe before anything else.

Conocybe apala. Same impossibly slender build, but the cap is whitish to pale cream rather than tan and the whole mushroom is even more short-lived. Common in the same lawns.

Panaeolina foenisecii. A lawn mushroom of similar size but sturdier, with a browner, often two-toned banded cap, mottled or unevenly darkening gills, and a dark purple-brown spore print instead of a rusty one.

Bolbitius titubans. Distinguished by a sticky, viscid, egg-yellow to buff cap that goes translucent and pleated, sitting on a whitish stipe. The print is rusty, but the viscid cap surface is unmistakable in the hand.

Galerina species. Usually on moss, rotting wood or wood debris, usually more robust and darker tawny, often with veil fibrils. Habitat plus overall stature does most of the separation.

Agrocybe pediades. Also a grassland species, but with a smooth hemispherical to convex tobacco-brown cap and a comparatively thick, tough, non-pruinose stipe.

Tubaria furfuracea. Grows on wood chips like some conecaps, but is convex rather than conical and carries whitish veil scurf on the cap margin.

A working sequence

Confirm grass, moss or mulch as substrate. Confirm the conical, hygrophanous, faintly striate tan cap. Confirm the wire-thin, pruinose, ringless stipe with a small basal bulb. Confirm rusty-brown spores. If all four hold, you are in Conocybe tenera in the broad sense; only microscopy will take you further.