Nigra

Nigra is a Latin feminine adjective meaning black. The base form is niger, with the neuter form nigrum. In scientific naming, nigra is frequently used as a specific epithet or subspecific epithet to describe dark coloration or other traits of a species. The epithet is not tied to any particular genus; it appears across many plants, animals, and fungi to indicate a dark feature, tone, or appearance, often color-related.

A well-known example is Quercus nigra, the water oak, a tree native to the eastern United States. The name reflects the dark wood or bark characteristic of the species in some contexts. Other examples occur in diverse groups, illustrating how taxonomic naming often encodes descriptive qualities rather than taxonomy alone.

Beyond biology, nigra can appear in Latin or pseudo-Latin phrases used in historical texts to describe colors or landscapes, and it appears in heraldic or descriptive language where Latin color terms appear in classifications.

In summary, nigra is a descriptive term borrowed from Latin used in modern nomenclature to indicate black or dark traits, most commonly encountered in species names within the biological sciences. Its feminine form pairs with feminine genus or species names, while masculine and neuter forms are used with their respective grammatical agreements.