pinnatus

Pinnatus is a Latin adjective meaning feathered or winged. In scientific usage it is most commonly found as an epithet in botanical and zoological names to describe feather-like or plume-like structures. The masculine form pinnatus is paired with feminine pinnata and neuter pinnatum, to agree with the gender of the genus.

In botany, pinnatus describes leaves that are pinnate, with leaflets arranged on opposite sides of a central rachis. It can also describe other structures with a feather-like arrangement, such as certain inflorescences or fern fronds. In botanical descriptions one might encounter phrases such as folia pinnata to indicate pinnate leaves.

In zoology, the term may describe plumage, hair, or other appendages that appear feathered or winged. As in botany, pinnatus is typically used as an descriptive epithet within a binomial name rather than as a standalone taxon.

Taxonomic usage and grammar: Pinnatus is not a genus or species by itself; it is an adjective used in species names. The form must agree in gender with the genus, producing pinnatus (masculine), pinnata (feminine), or pinnatum (neuter).

See also: pinnate, pinnation.