Viola impostor (Violaceae), a New Species from the Southeastern Atlantic Coastal Plain

While long recognized as a distinctive biotic region, the North American Coastal Plain has received increasing taxonomic attention in recent decades, resulting in many newly described species and resurrected older names. Recent intensive taxonomic studies in Viola subsect. Borealiamericanae (Acaulescent Blue violets) of eastern North America have supported recognition of more than 40 distinct evolutionary species, including several undescribed taxa and other long-neglected names requiring reinstatement or elevation in rank. A new southeastern Atlantic Coastal Plain endemic, Viola impostor, belonging to the Affinis species group, was previously confused with Viola affinis, V. cucullata, and Viola langloisii, but differs in features of leaves, chasmogamous flowers, cleistogamous capsules, and seeds. It grows in and around riparian baldcypress-swamps and deciduous floodplains from southeastern Virginia to eastern Georgia, where it is mostly restricted to the outer Atlantic Coastal Plain. A table of salient macromorphological traits and dichotomous keys to chasmogamous flowering and cleistogamous fruiting specimens distinguish the new species from others most similar to it. A diagnosis and description, plate of structures, specimen citations, ecological information, conservation assessment, and a geographic distribution map provide further details on V. impostor.