Comprehensive DescriptionRead full entry
CommentsAt first glance, the Marsh Violet can be easily confused with the Common Blue Violet (Viola pratincola) and other rosette-forming violets (Viola spp.) with blue-violet flowers. It can be easily distinguished from these other species, however, by the club-shaped hairs on its lateral petals (a 10x hand lens may be required to see this). The hairs of lateral petals on other violets are almost always evenly filiform (thread-like) and do not possess conspicuous swollen tips. The only other violet in Illinois with such hairs on its lateral petals is the rare Wayside Violet (Viola viarum). This latter species is easily distinguished from the Marsh Violet by its lobed leaves and its preference from dry habitats. Across its range, the Marsh Violet is rather variable in such characteristics as the shade of blue-violet on its petals, the shape of its leaves, the presence or absence of auricles (basal lobes) on its sepals, and the extent to which the flowers are held above the foliage. Although different varieties of the Marsh Violet have been described in other parts of North America, none of these are currently recognized in Illinois. The scientific name, Viola obliqua, is considered a synonym of this species.