illinoensis

Illinoensis is a Latin adjectival epithet used in scientific names to indicate origin from the state of Illinois. It is formed from Illinois with the common Latin locational suffix -ensis and is typically written in lowercase. The epithet is employed across taxonomic groups to signal that the type specimen was collected in Illinois, that the species is native to Illinois, or that its distribution includes the state.

As a geographic or toponymic epithet, illinoensis functions as a qualifier rather than a person’s name. The suffix -ensis is generally treated as invariable with respect to the gender of the genus, meaning the epithet remains illinoensis across masculine, feminine, and neuter genera in most modern usage. When a species is moved to a different genus, the epithet is usually retained, subject to the standard rules of Latin grammar and editorial practice.

The epithet illinoensis is common in regional floras and faunas of the Midwest and can be found across plants, animals, fungi, and microorganisms associated with Illinois. Its use reflects the historical and geographic context of species discovery and description, illustrating how taxonomy records the relationship between organisms and their locale.

In summary, illinoensis denotes a connection to Illinois within the binomial nomenclature, serving as a geographic descriptor that helps convey the origin or distribution of a species in a concise Latin form.