1 Corolla strongly frontally flattened in life; flower 'throat' yellow; spur short, up to 3 mm long; stipule deeply pinnately lobed with few to many lateral segment, the terminal lobe resembling the leaf blade; leaf blade linear-lanceolate to elliptical, base cuneate to truncate; plants annual or biennial, without thickish rootstock; [of weedy habitats].

  2 Petal shorter than the sepal or scarcely surpassing them by 1-2 mm, cream-white (slightly yellowish); sepal nearly or fully concealing capsule

  2 Petal well surpassing sepal, pale blue to violet (infrequently cream-white) or multicolored; sepal neither surpassing nor concealing capsule.

    3 Petal variously colored, commonly with the lower three petal cream-white and upper two purple-black; terminal lobe of stipule with 4 or more crenation on each side; quadrate stems recurved-puberulent on the angles; leaves cauline and commonly also basal.

      4 Flowers < 1 cm long in profile; lower three petal cream-white, upper two purple-black at least in distal half; [occasional escape]

      4 Flowers > 1.5 cm long in profile; all petal variously colored, often with broad black border; [barely persistent following cultivation]

1 Corolla not strongly frontally flattened in life; flower 'throat' white; stipule subentire to irregularly lacerate or laciniate but not deeply lobed with leaf-like terminal lobe; leaf blade ovate to reniform, base cordate; plants perennial, with thickish rootstock; [mainly of natural habitats].

        5 Current year’s stems ascending at chasmogamous flowering time, persistent through winter to become prostrate and root at the node, generating the following year's plants at their tips (plants thus mat-forming).

          6 Foliage glabrous except for small scattered subappressed hair on upper surface of leaf blade (especially near the margin), peduncle and stems glabrous; upper surface of leaf blade uniformly green; stipule weakly lacerate, with marginal process < ¼ as long as the stipule; [moist loam of riverbanks and lawns, Appalachian, rare]

          6 Foliage, peduncle and stems densely puberulent; upper surface of leaf blade silvery- to gray-green with darker green veins; stipule deeply laciniate with marginal process > ½ as long as the stipule; [sandy loam, commonly on dolomite ledges in our range, e. WV, w. VA and c. OH to FL, AR and e. TX]

        5 Stems ascending to erect at chasmogamous flowering time through fruiting, deciduous and not rooting at node (plants thus solitary).

             7 Corolla white (rarely pale violet), spurred petal with extensive dense nectar-guide lines; spur short, 1-2 mm; cauline leaf blade broader than long, ovate- to deltate-reniform; stipule subentire or minutely toothed; [native of temperate eastern and tropical Asia, introduced to NJ and NY]

             7 Corolla cream-white, blue or purple, spurred petal with few fine inconspicuous nectar-guide lines; spur moderately short to elongate, 3-7 mm; cauline leaves longer than broad to broader than long but not deltate; stipule weakly to strongly lacerate or fimbriate; [native species, collectively widespread in our region].

               8 Corolla wholly cream-colored; calyx ciliate; margin of leaf blade closely crenulate

               8 Corolla blue or pale violet; calyx eciliate; margin of leaf blade crenate or serrate.

                 9 Spur of basal petal 4-6 mm long; lateral petal bearded within; corolla uniformly blue

                 9 Spur of basal petal 10-15 mm long; lateral petal beardless; corolla pale violet with a purple-black eyespot surrounding the throat