*Viola arvensis Murray. Section: Melanium. Subsection: Bracteolatae. Phen: Chasmogamous flower Mar–Jul (-Aug); cleistogamous fruit May-Jun (-Aug). Hab: Roadsides, fields, other disturbed habitats. Dist: Native of Europe, widely introduced.
ID notes: This species is easily distinguished from V. rafinesquei by the petals nearly or fully surpassed by the sepals (the latter often largely concealing the mature capsule), the cream-white corolla (which is rare in the latter), and pinnatifid stipules with the terminal leaf-like lobe much larger and broader than the lateral lobes and having 4 or more crenations per side. It differs from V. tricolor by the pinnately divided stipules, sepals nearly equaling to fully surpassing the petals, and the cream-colored petals.
Origin/Endemic status: Europe
Taxonomy Comments: Apparently does hybridize rarely with V. tricolor (Ballard, Kartesz, & Nishino 2023).
Synonymy: = C, F, FNA6, G, GrPl, Il, K1, K3, K4, Mi, NE, Pa, RAB, S, Tn, Va, W, WV, Ballard () (in prep), Ballard, Kartesz, & Nishino (2023), McKinney & Russell (2002)