Viola baxteri House. Section: Nosphinium. Subsection: Borealiamericanae. Phen: Chasmogamous flower Apr–May (-Jul); chasmogamous fruit May-Jun; cleistogamous fruit Jun-Sep. Hab: Sandy or rocky loam of limestone prairies and prairie-like openings, often surrounded by richer mesic or swamp forests. Dist: C. NY to sw. Ont. and se. MI, south to sw. PA, sw. OH, nc. KY, and e. IN.
ID notes: The most extreme form of this species has the leaf blades biternate with the ultimate leaf divisions or segments narrowly linear and nearly as slender as those found in V. pedatifida. It shares with V. stoneana (a heterophyllous member of the Palmata species group) the unusual feature in Borealiamericanae violets of pale unspotted or weakly blotched seeds. It is most similar to other homophyllous cut-leaved taxa in the Pedatifida and Subsinuata species groups. Aside from the pale seeds, this species can be separated from V. brittoniana and V. pedatifida by its densely hirsute foliage, short rounded auricles, oblong or narrowly ovate ciliate obtuse to rounded sepals, glabrous spurred petal, and heavily spotted cleistogamous capsule on short prostrate peduncle. It differs from V. monacanora in its densely hirsute foliage, and oblong or narrowly ovate ciliate obtuse to rounded sepals. It can be distinguished from V. subsinuata by the several features of leaf dissection noted in the key, as well as the seed features. It is easily separated from V. tenuisecta in its densely hirsute foliage, biternately divided leaf blades, and oblong or narrowly ovate ciliate obtuse to rounded sepals.
Origin/Endemic status: Native
Synonymy: = Ballard, Kartesz, & Nishino (2023); = n/a – Pa; < Viola brittoniana Pollard – FNA6; < Viola pedatifida G.Don; < Viola subsinuata Greene