nigrescens

Nigrescens is a Latin descriptive epithet used in the scientific names of organisms. It is not a taxon itself but a modifier that indicates a dark or blackish coloration. As a species epithet, nigrescens appears in zoological, botanical, mycological, and microbiological contexts to highlight a characteristic trait of the species, such as dark pigmentation in the body, tissues, or structures.

Etymology and grammar: Nigrescens derives from the Latin word niger, meaning black, with the present participle suffix -escens, yielding "becoming black" or "blackened." In binomial nomenclature it functions as an adjective that agrees with the genus name in meaning and, in practice, is used in a form that is broadly invariant across gender for the species epithet.

Usage and interpretation: The epithet nigrescens is applied to diverse groups to draw attention to dark coloration without implying close biological relatedness to other taxa with similar epithets. It is one of several color-based descriptors used in taxonomy; others include nigra, niger, and related forms. The presence of nigrescens in a name signals a descriptive trait rather than a taxonomic rank or a statement about relationships among organisms.

See also: Latin and scientific naming conventions; color-based taxonomic epithets; taxonomic nomenclature.