hirta

Hirta is a Latin adjective meaning hairy or bristly and is commonly encountered in biological nomenclature as a species epithet. In botanical and zoological names, hirta indicates that a feature of the organism—such as hairs or a hairy surface—is notable. The corresponding masculine and neuter forms are hirtus and hirtum, while hirta remains the feminine form, agreeing with the gender of the genus name.

In taxonomy, hirta is used across diverse groups to describe physical characteristics. Because Latin adjectives must agree in gender with the genus, the form of the epithet can vary (hirta, hirtus, or hirtum) depending on the genus. The epithet itself conveys a descriptive trait rather than implying a relationship among species.

One well-known example is Euphorbia hirta, a tropical weed commonly studied in ethnobotany and pharmacology for its traditional medicinal uses. The epithet is often cited in botanical literature and can appear in many other species names, reflecting the widespread application of the term to describe hairiness in a variety of organisms.

Note that hirta as a term is distinct from Hirta, the name of the main island of the St Kilda archipelago in Scotland. The capitalized toponym is unrelated to the Latin descriptive epithet, though both share the same root word in Latin.