Setosus

Setosus is a Latin adjective meaning bristly or bristled, commonly used in biological nomenclature as a species epithet to describe organisms with a hairy, bristly, or spine-like surface.

In taxonomic names, setosus must agree in gender with the genus: setosus for masculine, setosa for feminine, and setosum for neuter. The epithet indicates the presence of setae (bristle-like structures) or a generally bristly texture on an organism, such as on leaves, seeds, exoskeletons, or body surfaces.

The term derives from Latin seta, meaning a bristle or hair. In botany and zoology, setosus is often used alongside related descriptors like hirsutus (hairy) or setifer (bearing setae). The English adjective setose is derived from the same root and used in similar descriptive contexts.

The epithet appears across many taxonomic groups, including plants, fungi, and animals, to denote a conspicuous bristly character. It is not a standalone taxon but a descriptor that can be embedded in numerous species names.

See also: setose; seta; bristle.