peculiaris

Peculiaris is a Latin adjective meaning "peculiar" or "distinctive." In biological nomenclature, peculiaris is widely used as a species epithet in the scientific names of living organisms. When employed in a binomial name, it signals that the taxon possesses a feature or set of features that the author considered unusual or noteworthy relative to related taxa.

The epithet is a grammatical adjective, and like other Latin epithets it must agree in gender with the genus name according to the rules of the relevant code (ICN for plants, algae, and fungi; ICZN for animals). As a result, the exact ending of the epithet can vary with the genus, but peculiaris is a common form that appears across many genera.

Not all uses of peculiaris convey a precise, quantifiable trait; sometimes the epithet reflects a historical aside, the collector's impression, or a perceived distinctive quality rather than a strictly defined criterion. Because taxonomic names are primarily descriptive, the rationale for its choice may be found in the original species description.

Peculiaris also appears in non-taxonomic contexts as a descriptor in scientific writing to indicate unusual or noteworthy features in organisms or specimens, and is sometimes encountered in informal or historical discussions of natural history.