Ebony Cup Identification Guide

The First Impression and the Setting

This is one of the earliest larger cup fungi of the year. The setting is damp conifer woodland - spruce, fir or pine - in late winter and spring, often within days or weeks of snow leaving the ground. You are looking at mossy banks, needle duff, the mossy sides of stumps, damp hollows and the margins of old skid tracks.

What you actually see is a scatter of small black discs sitting in green moss. Each is 1 to 2 cm across, and against the moss they look like drops of tar, spilled paint or small dark buttons. They are almost always gregarious, appearing in loose groups of a dozen or more, and sometimes in a line along a buried rotting branch under the moss layer.

The contrast is what finds them. Black on bright spring moss is conspicuous once you know to look, and a promising patch of moss under old spruce is worth ten minutes of slow searching.

Reading the Cup

Measure and describe the shape first. Fruitbodies are 0.5 to 3 cm across, shallowly bowl- or saucer-shaped when young, expanding to nearly flat with a gently wavy or slightly upturned rim in age. They are never deeply urn-shaped or goblet-like, and they never develop a torn, toothed margin.

The inner face is the fertile surface. It is smooth, matt to slightly glossy when wet, and a genuine jet black, sometimes with a faint olive or greenish-black cast when very fresh. As it dries it dulls and can look brownish-black, and old fruitbodies shrivel into hard black scraps that swell again after rain.

A young margin is distinctly incurved, so the cup looks half-closed, and it opens as the fruitbody matures.

The Outer Surface

Turn one over, and use a hand lens. This is where the genus declares itself.

The outside is blackish-brown and covered with fine, matted, dark brown to black hairs, giving a felty or velvety coating. The hairs are usually densest near the margin, where they often form a slight fringe that catches the light. Critically, there are no coloured granules, no rusty or orange-red flecks, and no scurfy scales of contrasting colour - the whole exterior is a uniform dark pelt.

Below, the cup narrows into a short stub-like stalk or attaches almost directly, with only a few millimetres of stem at most. That base is buried in moss or litter and is usually bound to needles, moss stems and rotten wood fragments by dark brown mycelium. Lift specimens with a knife blade rather than pulling, so the base and any attached substrate stay intact.

Flesh and Colour Change

Slice a fruitbody vertically. The flesh is only 1 to 2 mm thick and is blackish to dark grey-brown throughout - there is no pale interior layer to find.

The texture is firm and rubbery-gelatinous, not brittle and not sloppy. A fresh cup flexes and springs back when bent, and it resists tearing. There is no latex, no juice, and no colour change on cutting beyond the cut face looking wetter than the surface. That firm rubbery consistency is a useful way to distinguish this from the brittle-fleshed Peziza relatives, which crumble at a fold.

Taking a Spore Deposit

This is an ascomycete, so spores are shot upwards from the inner surface rather than falling from an underside, and there is a satisfying field test that exploits it. Bring a fresh collection into warm air, or simply breathe gently across the cups, and after a few seconds a visible puff of white smoke rises as thousands of asci discharge together. That instant confirms you are dealing with a cup fungus rather than a rubbery basidiomycete.

For an actual deposit, invert a mature cup over a piece of dark paper inside a closed container and leave it for several hours. The deposit is white.

Under the microscope the decisive character is spore shape. The spores are globose - genuinely spherical, not merely broad - smooth, colourless, roughly 10 to 14 micrometres in diameter, and often containing one or two oil drops. Round spores separate this genus from the ellipsoid-spored black cups it most resembles, and a single lens view usually ends the question.

Substrate and Season

The fungus is a decomposer working in conifer litter. Look for it on needle duff, on mossy soil, among carpets of feather moss, and on well-rotted conifer wood that has been swallowed by moss - often the wood is invisible until you probe with a finger.

Mature spruce and pine stands, shaded north-facing slopes, the edges of forest roads and the ground around old stumps are all productive. It shows a distinct preference for consistently damp ground rather than dry ridge tops.

The season is short and early: from the retreat of snow through mid or late spring, making it one of the first substantial fungi of the year in conifer country. Fruitbodies appear in groups and mature over one to two weeks, and by early summer they have shrivelled to black flakes in the moss.

Separating It From the Look-alikes

Pseudoplectania melaena. The closest relative, growing on rotten conifer wood rather than in moss and litter. It tends to be a little larger, browner-black, with a more distinct short stalk. Its spores are also globose, so this pair is separated on substrate, stature and fine microscopic detail rather than on any single field character. Record substrate carefully.

Plectania melastoma. Look at the outer surface with a lens: it carries reddish-orange to rusty granules that stand out clearly against the black ground. Its spores are ellipsoid, not round, and it favours hardwood twigs.

Plectania nannfeldtii. A black spring cup of high elevations, appearing near melting snow. It has a long, thin, black rooting stalk that can be several centimetres, so the fruitbody looks like a small wine glass or a black golf tee. Its spores are ellipsoid.

Urnula craterium. Far larger at 3 to 6 cm or more, deeply urn- or goblet-shaped with a distinctly toothed or torn margin, on a well-developed blackish stalk, and growing from buried hardwood sticks in spring. Nothing about its shape resembles a small flat disc.

Sarcosoma globosum. A large, heavy, gelatinous goblet 5 to 10 cm across, filled with jelly and sitting in spring spruce forest. Its bulk and wobbling contents are immediately different.

Bulgaria inquinans. Rubbery blackish discs clustered on fallen oak and beech bark, mainly in autumn. Its fertile surface is shiny black, its outer surface scurfy brown, and its spore deposit is dark brown to blackish rather than white. Substrate, season and print all differ.

Dark Peziza species and Ascocoryne. Peziza species that darken are brown rather than black and lack the dense hairy exterior, and their flesh is brittle. Ascocoryne is purple to purplish-black, gelatinous and clustered on hardwood.

A Working Sequence

Note conifer woodland and a spring date. Confirm a small shallow black cup 1 to 3 cm across sitting in moss or litter. Check the exterior with a lens for a uniform dark hairy coating with no coloured granules. Confirm dark rubbery flesh throughout. Check for at most a short stub of a stalk. Breathe on the collection to see the spore puff, then look for perfectly spherical spores if you have a microscope.