A Revised Phylogenetic Classification for Viola (Violaceae)

Area of Science:

• Botany
• Plant Taxonomy
• Phylogenetics

Background:

• The genus *Viola* (Violaceae) is a large angiosperm genus with a complex taxonomy that has not been revised since 1925.
• The last revision by Wilhelm Becker classified 400 species into 14 sections and numerous unranked groups.

Purpose of the Study:

• To provide an updated, comprehensive classification of the genus *Viola* based on modern phylogenetic principles and integrated data.
• To establish a global checklist of accepted *Viola* species and define infrageneric subdivisions.

Main Methods:

• Phylogenetic analyses using multigene and ITS data with dense taxon sampling.
• Integration of morphological data, chromosome counts, and ploidy information.
• Application of modern principles of monophyly for taxonomic revisions.

Main Results:

• A revised classification recognizing 664 species within 2 subgenera, 31 sections, and 20 subsections.
• Establishment of one new subgenus (*Neoandinium*), six new sections, and seven new subsections.
• Detailed accounts for each infrageneric subdivision, including descriptions, apomorphies, and distribution maps.

Conclusions:

• The study provides a robust, modern taxonomic framework for the genus *Viola*.
• Significant knowledge gaps exist for South American *Viola* taxa, requiring further research in phylogeny, chromosome counts, and fossil data.
• Future studies should focus on seed anatomy and morphology to better understand the genus's fossil record and evolutionary history.