pilosum

Pilosum is a Latin adjective meaning hairy or pilose, used in the scientific naming of organisms to describe a characteristic feature. In taxonomic practice, pilosum (neuter), pilosa (feminine), and pilosus (masculine) function as a specific epithet that can accompany a genus name to form a species designation. The epithet is widely applied across diverse groups, including plants, animals, and fungi, and appears in many genera.

As a descriptive term within binomial nomenclature, pilosum signals that the species bears noticeable hair-like structures such as trichomes, fine hairs on leaves or stems, or hairy seeds or fruits. The use of pilosum is not a stand-alone taxon; it is an attribute attached to a genus name to form a species name.

Gender agreement is a key rule in Latin grammar: the epithet must match the gender of the genus. Thus, pilosus is used with masculine genera, pilosa with feminine genera, and pilosum with neuter genera. The choice follows standard taxonomic conventions and does not convey ranking beyond the species designation.

Etymology notes that pilosus derives from pilus, meaning hair, and the related term pilose describes hairiness. In practice, researchers citing a species with pilosum may refer to the hairy surface or texture as a distinguishing feature in taxonomic descriptions and identification keys.