artengruppen

Artengruppen are informal groupings used in taxonomy to organize closely related species within a genus. They denote sets of species that share significant similarities or common ancestry, without representing a formal rank in nomenclatural codes. The exact composition and boundaries of an Artengruppe can vary among authors and studies.

Because they are not formal taxonomic categories, Artengruppen are defined and revised ad hoc. Delimitations typically rely on multiple lines of evidence, including morphology, cytology, genetics (such as DNA sequences and phylogenetic analyses), geographic distribution, and ecological traits. Boundaries can be fuzzy, and groups may be redefined as new data emerge. The concept often overlaps with terms like species complex or clade.

In practice, scientists use Artengruppen to discuss and illustrate relationships within a genus, for example in monographs, revisions, or field guides. They provide a practical way to refer to a cluster of closely related species without committing to a formal taxonomic rank that requires explicit nomenclatural actions.

With advances in molecular phylogenetics, the idea of an Artengruppe frequently corresponds to what is described as a clade or a species group in modern literature. Nevertheless, Artengruppen remain nonstandard, fluid constructs that reflect current understanding rather than fixed, codified categories.

Etymology-wise, the term combines Art (species) and Gruppe (group). See also species group, species complex, clade, and related concepts in taxonomy.