Crimson Cup

The Crimson Cup is among the most striking fungi of the late-winter woodland, its deep scarlet bowls glowing against wet leaf litter and moss when almost nothing else is fruiting. It belongs to Sarcoscypha, a small genus in the family Sarcoscyphaceae whose members all share vividly red, tough-fleshed cups borne on decaying hardwood.

The contrast between the two surfaces is the signature of the genus: the inner spore-bearing face is intensely red, while the outer face is whitish to pale pink and clothed in a fine, matted downy layer of hairs. Fruiting bodies are attached to a stick or branch fragment by a short stalk that is often hidden under litter, so the cups can appear to emerge directly from the ground.

The genus is notoriously difficult at species level. Sarcoscypha coccinea in the strict sense is separated from its close relatives largely by microscopic detail — the shape of the spore ends and the curling of the outer hairs — so many field records are best treated as belonging to the coccinea group.

Fruiting body

The cup is 1–5 cm across, occasionally to 7 cm, deeply bowl-shaped when young and expanding to a shallower saucer with an even or slightly inrolled, sometimes minutely toothed margin.

Surfaces

The inner surface is smooth and vivid scarlet to crimson, retaining its colour well and fading only in old or sun-bleached specimens. The outer surface is whitish, cream or pale pinkish and covered in a fine matted down of tangled hairs, giving it a slightly felted appearance.

Stipe

There is usually a short, whitish, tapering stalk 0.5–3 cm long, often buried in litter or moss and attached directly to a hardwood stick. In some specimens it is barely developed.

Flesh & spore print

The flesh is thin, whitish to pinkish, and noticeably tougher and more pliant than in Peziza — it flexes rather than snapping cleanly. The spore print is white. Spores are large, smooth and elliptical, and often carry oil droplets at each end.

Crimson Cup fruits on fallen hardwood sticks, twigs and small branches lying on damp ground, very often on wood that is partly or completely buried under leaf litter or moss. Willow, hazel, elm, maple, beech and other broadleaved trees are typical hosts. It favours moist, sheltered woodland — stream sides, damp valley bottoms, shaded ravines and mossy banks.

The season is unusual: fruiting begins in late winter, sometimes while snow is still patchy on the ground, and continues through early and mid spring, tailing off as temperatures rise. It is widely distributed across temperate Europe and North America, and its early appearance makes it one of the first conspicuous fungi of the year.

This is a saprophytic wood decomposer. Its mycelium colonises small-diameter fallen hardwood, particularly wood in prolonged contact with damp soil, and breaks down the cellulose and lignin of the branch from the inside. Colonised sticks often feel light and slightly spongy, and pulling one from the litter usually reveals the cups still attached along its length.

The cold-season fruiting strategy has clear advantages: competition from other wood-rotting fungi is minimal, humidity is high, and the bare canopy allows air movement across the forest floor. Spores are discharged from the asci on the inner face in the usual operculate manner, and the bright colouring may aid dispersal by attracting insects and other small animals to the cups.

Sarcoscypha austriaca is essentially identical in the field and is separated microscopically by its spores, which are rounded rather than flattened at the ends, and by the tightly curled hairs on the outer surface; it is frequently the commoner species in parts of Europe. Sarcoscypha dudleyi is another near-twin in eastern North America, distinguished by spore characters and often by a paler outer surface.

The Stalked Scarlet Cup (Sarcoscypha occidentalis) is much smaller, with a cup usually under 2 cm carried on a slender, clearly visible whitish stalk, and it fruits in late spring and summer rather than late winter. Microstoma floccosum has a deeper, more goblet-shaped red cup fringed with conspicuous shaggy white hairs. Orange Aleuria aurantia is a ground-dwelling autumn species with an orange rather than scarlet cup and no downy exterior or stalk.