1 Flowers in opposite 3-flowered cymules, borne in terminal clusters subtended by connate leaves; corolla red, yellow, orange, or creamy white; twining vine or shrub with vining tendencies (in L. flava the "vininess" sometimes not apparent).

  2 Corolla creamy white, 12-18 mm long; [OK and TX westwards]

  2 Corolla red, yellow, or orange, 10-50 mm long; [collectively widespread].

    3 Corolla tube (20-) 30-50 mm long; corolla lobes 4-8 mm long, bilaterally symmetrical but not strikingly so; [of a wide variety of habitats, primarily in the Piedmont and Coastal Plain]

    3 Corolla tube 10-35 mm long; corolla lobes 8-15 mm long, strongly bilaterally symmetrical, unequally divided into 2 lips (4 lobes on the upper side and one lobe on the lower side); [of ridgetops, rocky slopes, granite domes, and bogs of the Mountains, or of areas to the north or west of the primary area].

      4 Leaves pubescent on the upper surface; [of moist forests, south to PA]

      4 Leaves glabrous on the upper surface.

        5 Fused leaves immediately below the inflorescence broadly rounded or emarginate, usually glaucous on the upper surface; seeds 4.5-5.0 mm long; [of c. TN, and westward and northward]

        5 Fused leaves immediately below the inflorescence, acute or obtuse and also mucronate, green on the upper surface; seeds 3.0-3.5 mm long.

          6 Corolla tube 20-35 mm long, symmetrical below; leaves weakly gray-glaucous beneath; [of soil mats on dome outcrops of s. NC, SC, and GA and westward]

          6 Corolla tube 15-25 mm long, with a swelling near the base on one side; leaves strongly white-glaucous beneath; [of rocky forests, ridgetops, and bogs of n. NC, VA, and northward]

1 Flowers in peduncled pairs in the axils of leaves, not subtended by connate leaves; corolla white to pastel pink or yellow; plant an erect shrub or (L. japonica) a trailing or climbing vine.

             7 Trailing or climbing vine; corolla 30-50 mm long; fruit black at maturity; leaves of vigorous shoots often pinnately lobed

             7 Upright shrub; corolla 7-25 mm long; fruit red or yellow at maturity; leaves unlobed.

               8 Branches with solid and continuous, white pith; [native and exotic species].

                 9 Corolla lobes 5, nearly equal; ovaries separate, divergent; [native species of cool moist forests and bogs].

                   10 Ovaries fused; fruit blue; bractlets subtending the flowers 4-6 mm long; [PA northwards]

                 9 Corolla lobes fused into a 4-lobed upper lip and a 1-lobed lower lip; ovaries fused; [exotic and native species].

                     11 Flowers yellow; flowers appearing after the leaves; [native species, PA northwards]

                     11 Flowers white to purplish; flowers appearing before the leaves; [exotics].

                       12 Branches glabrous; corolla glabrous on the exterior

                       12 Branches retrorsely hispid with reddish-brown hairs; corolla pilose on the exterior

               8 Branches hollow between the nodes, with tannish pith; [exotic species, many of them seriously invasive and likely to be encountered in natural areas].

                          13 Peduncles shorter than or equal to the subtending petiole; leaves ovate (broadest near the base) and distinctly long-acuminate

                          13 Peduncles longer than the subtending petiole; leaves elongate (broadest near the middle) and obtuse to acute (rarely short-acuminate).

                            14 Leaves glabrous; peduncles 15-25 mm long

                            14 Leaves pubescent, at least on the lower surface; peduncles 5-15 mm long.

                              15 Corolla pink (aging to yellow), nearly glabrous on the exterior, barely bulging on one side at the base; leaves thinly pubescent beneath

                              15 Corolla white (aging to yellow), pubescent on the exterior, distinctly bulging on one side at the base; leaves rather densely grayish-pubescent beneath.

                                16 Bracts and sepals ciliate, not glandular; ovary lacking glands; leaf blades broadest at or below the middle

                                16 Bracts and sepals glandular; ovary glandular; leaf blades broadest beyond the middle