Scarlet Elf Cup

The Scarlet Elf Cup is one of the most photographed fungi in temperate woodland, and deservedly so: a scatter of bright red discs on a mossy fallen branch in the middle of winter is a striking sight when almost nothing else is fruiting. Its intense colour comes from carotenoid pigments concentrated in the fertile inner surface.

It is an ascomycete in the family Sarcoscyphaceae. The whole fruiting body is essentially an open cup, or apothecium - the fertile hymenium lines the inner face, and microscopic spore-shooting asci packed across that surface discharge their spores upward into the air. On a still day, tapping a ripe colony can produce a faint visible puff.

Two very similar species are involved in most records. Sarcoscypha austriaca is the commoner in northern and western Europe, while Sarcoscypha coccinea is more southern and continental; they are separated reliably only by microscopic details of the spores and hairs, and many field records simply use one name for both.

Fruiting body

A shallow to deep cup or saucer, 1-5 cm across (occasionally to 7 cm), at first almost closed and urn-like, later expanding to a broad open bowl with an incurved, often slightly irregular or wavy margin. It sits on a short, whitish, tapering stalk 0.5-3 cm long which is frequently buried in moss or the decaying wood beneath.

Inner surface

The fertile face is smooth, waxy and a brilliant, saturated scarlet to vermilion, occasionally fading to orange-red in older or sun-exposed specimens and very rarely to white or yellow in albino forms.

Outer surface

Markedly different: whitish to pale pink or pale buff, dull, and covered with a dense felt of fine matted hairs which give a slightly frosted or downy appearance under a hand lens. This strong two-tone contrast between red inside and pale felty outside is a good field character.

Flesh and spore print

Flesh is thin, firm-rubbery and pale reddish. Spore print white. Spores are large, elliptical, smooth and typically flattened or truncated at the ends in S. austriaca, often producing conidia at each end - a microscopic feature used to distinguish it from S. coccinea.

This species grows on fallen, damp, well-rotted sticks and branches of broadleaf trees, usually those lying in shaded, humid situations and often partly buried in moss, leaf litter or wet soil. Willow, hazel, elm, beech, sycamore, maple and alder are common hosts, and it particularly favours damp woodland, streamsides, wet flushes, riverbanks and shaded ditches.

It is a cold-season fungus, fruiting from late autumn through winter and into early spring, with peak records typically from January to April. The sticks it grows on are often invisible beneath moss, so cups can appear to spring directly from the ground; tracing the stalk downward usually reveals the buried wood. It is widespread throughout temperate Europe and North America.

Sarcoscypha austriaca is a saprotroph of small-diameter hardwood debris. Its mycelium colonises fallen twigs, sticks and branches lying in wet, mossy conditions, breaking down cellulose and lignin in wood that is already softened, and it is part of the community that converts fine woody litter into forest soil.

The winter fruiting season is a genuine ecological strategy rather than an accident. Competition from faster-growing fungi is low in cold months, the moss keeps the substrate constantly moist, and the leafless canopy allows better air movement for spore dispersal. Spores are shot actively from the asci lining the cup, and the cup shape itself works to funnel and direct the discharge upward out of the still layer of air just above the ground. Some evidence suggests the bright pigment also aids in tolerating light exposure, and possibly attracts small arthropods that may assist secondary dispersal.

Sarcoscypha coccinea is essentially identical to the eye - the two are separated only by microscopic spore shape and the coiled or straight nature of the outer hairs - and both are commonly labelled Scarlet Elf Cup. Geography helps: S. austriaca dominates in the north and west of Europe.

The Orange Peel Fungus (Aleuria aurantia) is bright orange rather than scarlet, has no stalk, is thin and brittle, becomes irregularly contorted and split like discarded peel, and grows on bare disturbed soil and path edges in autumn, not on winter sticks. The Eyelash Cup (Scutellinia scutellata) is much smaller, only a few millimetres to about 1 cm across, flat rather than deeply cupped, and ringed with conspicuous stiff black hairs around its margin. Caloscypha fulgens is orange with bluish-green bruising on the outer surface and is a spring species of conifer forests.