Shaggy Scarlet Cup

Shaggy Scarlet Cup (Microstoma floccosum, formerly placed in Sarcoscypha as S. floccosa) is a small member of the Sarcoscyphaceae, the family of scarlet cup fungi. Where most of its relatives are broad, smooth-sided bowls, this species is a narrow goblet or funnel, and its outer surface is covered in conspicuous, matted white hairs.

The fruit bodies are small — rarely more than 2 cm across the mouth — but they usually appear in troops of several to dozens along a decaying buried branch, and the contrast of scarlet against white is visible from some distance on a dark forest floor.

It is a warm-season species in deciduous forests, replacing the early-spring scarlet cups that fruit before leaf-out.

Fruiting body

A goblet or deep funnel 0.5–2 cm across the mouth, tapering gradually into the stalk. Young specimens are almost closed, opening by a small round mouth that widens and often splits into irregular lobes at the rim.

Surfaces

The inner surface is a clean scarlet to orange-red, smooth and slightly shining when moist. The outer surface is whitish to pale pink and densely covered with long, tangled, woolly hairs that project beyond the rim as a shaggy fringe.

Stipe

The stalk is slender, 1–4 cm long, whitish, hairy like the cup, and usually rooted in a buried stick so that it appears to arise from bare soil or leaf litter.

Flesh and spore print

Flesh is thin and rubbery-firm rather than gelatinous. The spores are large, smooth and elliptical, producing a whitish print.

It fruits on decaying hardwood sticks and small branches, almost always buried or half-buried in leaf litter and soil, in moist deciduous and mixed forest. Oak, maple, beech and hickory litter are typical settings, and it favours shaded stream banks, ravines and damp bottomland.

The season runs from late spring through summer, later than the spring scarlet cups. It is well known in eastern North America and is also reported from East Asia, with related species elsewhere in the world.

Microstoma floccosum is a wood-rotting saprophyte specialising in small-diameter hardwood debris in contact with damp soil. The colonised stick is often mostly decayed and easily missed, so the cups look as though they arise from the ground until the litter is teased away.

Several fruit bodies typically emerge from the same buried branch over a period of weeks, releasing spores that are forcibly discharged from the exposed inner surface of the goblet.

Sarcoscypha austriaca and S. coccinea are much broader, shallower bowls with only fine whitish down on the outside, are effectively stalkless or short-stalked, and fruit in late winter to early spring on exposed hardwood sticks. Sarcoscypha occidentalis is closest in size but has a smooth, hairless outer surface and a thin, bare, sharply defined stalk. Tropical Cookeina species are similarly goblet-shaped and fringed but are pink to salmon rather than pure scarlet and occur in the tropics.

The dense white shaggy coating of the outer cup, projecting past the rim, is the deciding feature in temperate forests.