Veined Cup

The Veined Cup is a spring ascomycete in the family Morchellaceae, the same family as the true morels, and its close relationship shows in the microscopic details and in its habitat rather than in its shape. Where a morel raises a pitted head on a stalk, Disciotis venosa stays low and spreads into an open disc.

The genus Disciotis is small and this is by far its best known member. Its defining features are the size of the fruiting body, which is large for a soil-dwelling cup fungus, the network of thick radiating veins on the fertile surface, and a distinctive chlorine-like smell noticeable when a fresh specimen is picked up.

Because it appears at the very start of the spring fungus season and often in the same damp hardwood ground as morels, it is a useful seasonal marker for anyone tracking the progress of spring fruiting.

Fruiting body

Starts as a deep, thick cup 2-5 cm wide and expands into a broad, flattened, plate-like disc commonly 5-15 cm across and occasionally larger. Mature specimens spread irregularly, with a wavy, often split or torn margin, and frequently sit half-buried in soil or litter.

Fertile (inner) surface

Dull brown, olive-brown, or dark tan, matt rather than glossy. The centre is raised into a system of thick, blunt, radiating and interconnecting veins and wrinkles; toward the margin the surface becomes smoother. These veins are the single most recognisable field character.

Outer surface and base

Much paler - whitish, buff or cream - and finely mealy, granular or scurfy to the touch. There is no true stalk, only a short, thick, whitish rooting base that anchors the disc into the soil.

Flesh, odour and spore print

The flesh is white, brittle and about 2-4 mm thick, breaking cleanly. Fresh material gives off a strong chlorine or swimming-pool odour, strongest when the fruiting body is first handled. The spore deposit is white to cream, and the spores are smooth and ellipsoid, in keeping with its morel relatives.

The Veined Cup grows on damp, rich, often calcareous soil in deciduous woodland, along riverbanks and stream terraces, on floodplains and in damp grassy woodland margins. It is frequently associated with ash, willow, poplar, elm and alder, and appears in the same disturbed, moisture-holding ground that produces spring morels.

Fruiting occurs early in spring, often before the tree canopy has closed, and can be over quickly once the soil dries. The species is widespread across temperate Europe and occurs in temperate North America and parts of Asia, though it is easily overlooked because the flat brown discs blend into wet leaf litter.

Disciotis venosa is saprotrophic, living on decaying plant material and humus in the upper soil layers. It thrives in ground enriched by seasonal flooding, where silt and rotting leaves accumulate, and its mycelium works through this organic matter in the months before fruiting.

The open, upward-facing disc is a highly efficient spore-launching surface: mature asci discharge their spores directly into moving air, and a disturbed specimen can release a visible smoky cloud. Fruiting depends on a narrow window of warming soil combined with high moisture, which is why the species is reliably found in flood-prone ground and along watercourses.

Large Peziza species such as Peziza badia and Peziza varia share the brown, soil-dwelling cup form but keep a smoother inner surface with no strong radiating veins, are usually more deeply cup-shaped for longer, and lack the chlorine-like odour. Most also fruit later in the year.

Gyromitra perlata is thicker-fleshed and grows on rotten conifer wood rather than bare damp soil, and it has a short ribbed stalk base. Discina and Disciotis material can also be confused with young, still-flattened specimens of Gyromitra species, but those develop lobed or brain-like heads while the Veined Cup only ever flattens further. Very large Helvella acetabulum has strong ribs running up the outside of the cup, the opposite of the Veined Cup, which carries its veins on the inner face and has a plain mealy exterior.