Sarcoscypha coccinea, commonly known as the scarlet elf cup, scarlet elf cap, or the scarlet cup, is a species of fungus in the family Sarcoscyphaceae of the order Pezizales. The fungus, widely distributed in the Northern Hemisphere, has been found in Africa, Asia, Europe, North and South America, and Australia. The type species of the genus Sarcoscypha, S. coccinea has been known by many names since its first appearance in the scientific literature in 1772. Phylogenetic analysis shows the species to be most closely related to other Sarcoscypha species that contain numerous small oil droplets in their spores, such as the North Atlantic island species S. macaronesica. Due to similar physical appearances and sometimes overlapping distributions, S. coccinea has often been confused with S. occidentalis, S. austriaca, and S. dudleyi.
The saprobic fungus grows on decaying sticks and branches in damp spots on forest floors, generally buried under leaf litter or in the soil. The cup-shaped fruit bodies are usually produced during the cooler months of winter and early spring. The brilliant red interior of the cups—from which both the common and scientific names are derived—contrasts with the lighter-colored exterior. The edibility of the fruit bodies is not clearly established, but its small size, tough texture and insubstantial fruitings would dissuade most people from collecting for the table. The fungus has been used medicinally by the Oneida Indians, and also as a colorful component of table decorations in England. Molliardiomyces eucoccinea is the name given to the imperfect form of the fungus that lacks a sexually reproductive stage in its life cycle.
The species was originally named Helvella coccinea by the Italian naturalist Giovanni Antonio Scopoli in 1772. Other early names include Peziza coccinea (Nikolaus Joseph von Jacquin, 1774) and Peziza dichroa (Theodor Holmskjold, 1799). Although some authors in older literature have applied the generic name Plectania to the taxon following Karl Fuckel's 1870 name change (e.g. Seaver, 1928; Kanouse, 1948; Nannfeldt, 1949; Le Gal, 1953), that name is now used for a fungus with brownish-black fruit bodies. Sarcoscypha coccinea was given its current name by Jean Baptiste Émil Lambotte in 1889.
Obligate synonyms (different names for the same species based on one type) include Lachnea coccinea Gillet (1880), Macroscyphus coccineus Gray (1821), and Peziza dichroa Holmskjold (1799). Taxonomic synonyms (different names for the same species, based on different types) include Peziza aurantia Schumacher (1803), Peziza aurantiaca Persoon (1822), Peziza coccinea Jacquin (1774), Helvella coccinea Schaeffer (1774), Lachnea coccinea Phillips (1887), Geopyxis coccinea Massee (1895), Sarcoscypha coccinea Saccardo ex Durand (1900), Plectania coccinea (Fuckel ex Seaver), and Peziza cochleata Batsch (1783).
Sarcoscypha coccinea is the type species of the genus Sarcoscypha, having been first explicitly designated as such in 1931 by Frederick Clements and Cornelius Lott Shear. A 1990 publication revealed that the genus name Sarcoscypha had been used previously by Carl F. P. von Martius as the name of a tribe in the genus Peziza; according to the rules of Botanical Nomenclature, this meant that the generic name Peziza had priority over Sarcoscypha. To address the taxonomical dilemma, the genus name Sarcoscypha was conserved against Peziza, with S. coccinea as the type species, to "avoid the creation of a new generic name for the scarlet cups and also to avoid the disadvantageous loss of a generic name widely used in the popular and scientific literature". The specific epithet coccinea is derived from the Latin word meaning "deep red". The species is commonly known as the "scarlet elf cup", the "scarlet elf cap", or the "scarlet cup fungus".