Viola incognita Brainerd. Section: Plagiostigma. Subsection: Stolonosae. Phen: Chasmogamous flower Apr-Jun; chasmogamous fruit Jun; cleistogamous fruit Jun-Sep. Hab: Moist to wet forests. Dist: NL (Labrador) to MN and ne. ND, south to DE, PA, and WI, and in the Appalachians south to w. NC.
ID notes:Nonreproductive plants and younger chasmogamous flowering plants of this species can be particularly challenging to distinguish from V. blanda, and from V. renifolia if the rhizome and any stolons present are not collected. This species is most similar to other Stolonosae violets with leaf blades nearly as broad as to broader than long. In chasmogamous flower it differs from V. palustris and V. suecica in its noncreeping rhizome, leaves forming a discrete rosette, and white corolla; from V. blanda in its occasionally hirsute petioles and lower surface of leaf blades, and densely bearded lateral petals; from V. minuscula in its occasionally hirsute leaf laminas and noticeably serrate leaf blade margins, and from V. renifolia by its threadlike stolons, foliage often sparsely hirsute, leaves ascending, leaf blades commonly ovate to broadly ovate, and lateral petals densely bearded. It can be distinguished in cleistogamous fruit from V. minuscula, V. palustris, and V. suecica by the rhizome and foliage characters noted above as well as its heavily purple-spotted or -blotched cleistogamous capsules and brown seeds; from V. blanda in producing summer stolons mostly lacking leaves and fruits along its length (but terminating in a plantlet), petioles and lower surface of leaf blades occasionally hirsute, leaf blades more broadly ovate to ovate-deltate with deeper broader basal sinus and obtuse apex, and seeds larger, more narrowly obovoid and lighter brown; and from V. renifolia by its horizontal stoloniform rhizomes and threadlike stolons, foliage often sparsely hirsute, ascending leaves, and leaf blades commonly ovate to broadly ovate.
Origin/Endemic status: Native
Synonymy: = S, Va, WV, Ballard, Kartesz, & Nishino (2023); = Viola blanda Willd. var. palustriformis A.Gray – K1, K3, K4, Mi, NE, Ballard () (in prep), Haines (2001); < Viola blanda Willd. – C, FNA6, Pa, RAB, McKinney & Russell (2002); > Viola incognita Brainerd var. forbesii Brainerd – F, G; > Viola incognita Brainerd var. incognita – F, G