1 Shrubs to 2 m tall, erect; stems hollow

1 Herbaceous vines (trailing or twining) or herbs (erect); stems solid or hollow.

  2 Corollas campanulate, the tube < 2× as long as its diameter; fruit indehiscent; [Old World Clade].

    3 Young stems glabrous; leaf undersurfaces glabrous; corollas lavender (purple, rose, or white), darker in the tube, 6-7 cm long

    3 Young stems densely white-hairy; leaf undersurfaces white-hairy; corollas cream-white, with pale yellow pleats and with maroon markings in the tube, 2.5-3 cm long

  2 Corollas salverform or funnelform, the tube > 4× as long as its diameter; fruit a dehiscent capsule.

      4 Corollas salverform, the long narrow tube cylindrical (with sides more-or-less parallel) for most of its length, the limb abruptly flaring at the summit of the tube.

        5 Corollas 3-15 cm long, predominantly lavender to white; flowers open from evening until early morning.

          6 Leaves tomentose beneath; corolla mostly white on the outer surface, lavender to purple on the inner surface, thus bicolored in-and-out; [of outer Coastal Plain dunes, hammocks, and shell middens from se. NC southward]

          6 Leaves glabrous (or with scattered hairs or large fleshy hairlike structures) beneath; corolla either white on both surfaces or lavender on both surfaces, not bicolored in-and-out; [weedy, widespread, of disturbed habitats].

             7 Sepals obtuse, 10-25 mm long.

               8 Corollas lavender, the throat darker; stems bearing dark, fleshy, hairlike structures; [non-native, rare introduction]

               8 Corollas white, with 5 yellowish lines; stems glabrous; [native, s. and c. peninsular FL]

             7 Sepals acute to caudate, 6-14 mm long.

                 9 Corollas 10-14 cm long, white with 5 greenish or yellowish lines; fruits 2-3 cm long, borne on dry pedicels

                 9 Corollas 3-7.5 cm long, whitish to violet or lavender; fruits 1.8-2 cm long, the pedicels fleshy

        5 Corollas 1.4-5 cm long, red, orange, or yellow; flowers open from early morning to late morning or late afternoon.

                   10 Corolla tubes 3-4 mm in diameter; plants perennial from tubers; [s. FL]

                   10 Corolla tubes 1-3 mm in diameter; plants annual from fibrous roots; collectively widespread in our region]; [Quamoclit Clade].

                     11 Leaf blades pinnately divided into 11-31 (or more) linear or lanceolate segments (with parallel sides or narrowing towards the base)

                       12 Leaf blade segments 11-19, lanceolate, 3-7 mm wide, parallel-sided near the base or narrowing towards the base, the apical portion of the segment narrowly triangular

                       12 Leaf blade segments 11-31 (or more), linear, < 2 mm wide, parallel-sided

                     11 Leaf blades entire, or angled, or shallowly to deeply palmately 3-7-lobed (and then the lobes broadening towards their bases).

                          13 Leaf blades deeply 3-7-lobed

                          13 Leaf blades unlobed (not counting the cordate base), or with leaves shallowly 3-lobed.

                            14 Inner sepals 4-6 mm long; pedicels becoming reflexed in fruit; leaves usually unlobed (though sometimes with a few coarse dentate teeth)

                            14 Inner sepals 2-3 (-4) mm long; pedicels remaining erect in fruit; leaves usually 3-lobed about halfway from margin to base

      4 Corollas funnelform, the short to long tube expanding in diameter upwards from below the middle, the limb gradually to abruptly flaring at the summit of the tube.

                              15 Pedicels and peduncles with spreading, ascending, or reflexed trichomes; gynoecium 3-parted; sepals 8-25 (-30) mm long; corollas deep purple to rich blue or light blue (rarely white or bright pink), the tube and throat lighter in color (white or yellow); [Pharbitis clade].

                                16 Sepals soft-pilose on the outer surface with slender trichomes

                                16 Sepals hispid-pilose on the outer surface, with swollen-based trichomes.

                                  17 Corolla pink to purple (rarely white or blue); sepals oblong-lanceolate, merely obtuse or acute and without a prominently narrowed (caudate) tip; leaves entire or 3-5-lobed

                                  17 Corolla blue with a white tube (drying pink); sepals ovate with an elongate or caudate apex longer than the sepal body, notably accrescent in fruit; leaves usually 3-lobed.

                                    18 Sepals < 2 cm long at anthesis, abruptly narrowed upwards, the long subacute tips strongly spreading or recurved outwards; corolla < 3.5 cm long; peduncles very short.

                                    18 Sepals ca. 3 cm long at anthesis, gradually narrowed upwards, the long acute tips suberect, straight, scarcely spreading; corolla 4-4.5 cm long; peduncles long or short

                              15 Pedicels and peduncles glabrous or with short, appressed trichomes; gynoecium 2-parted; sepals 4-15 mm long; corollas mainly pink, lavender, or white, the tube and throat mainly deeper pink, purple, or maroon (but some species – I. tricolor, I. aristolochiifolia -- blue with white or yellow throats).

                                       19 Leaves palmately, pinnately, or pedately compound or pseudocompound (so deeply parted as to appear superficially compound).

                                         20 Leaves pedately compound, the leaflets or segments 1.5-3 mm wide; corollas 1-1.2 cm long, white; [TX]

                                         20 Leaves palmately or pedately compound, the leaflets or segments 3-10 mm wide; corollas 1.8-6 cm long, lavender, pink, or purplish.

                                           21 Corollas 4-6 cm long; pedicels 1-2.5 cm long, straight; leaves pinnately dissected (the pair of lobes about the basal pair diverging from the midvein several mm above the basal pair); axillary buds developing stipule-like leaves

                                           21 Corollas 1.8-3 cm long; pedicels 5-10 cm long, spiraled; leaves palmately dissected; axillary buds not developing leaves

                                       19 Leaves simple, either unlobed or with 2-7 shallow lobes.

                                             22 Leaves linear, 2-8 mm wide, > 10× as long as wide; stems erect to ascending, bushy-branched, neither trailing nor twining

                                             22 Leaves broader, > 20 mm wide, < 5× as long as wide; stems either trailing or twining.

                                               23 Stems trailing, rooting at the nodes; leaf apex emarginate, truncate, obtuse, or acute.

                                                 24 Corollas lavender; larger leaves not lobed (though notched at the apex on at least the larger, better-developed leaves of I. brasiliensis)

                                                    25 Leaves rounded, acute, or short-acuminate at the apex; sepals unequal, the outer 5-6 mm long, , thicker and about 1/2 as long as the herbaceous inner sepals

                                                    25 Leaves emarginate at the apex; sepals essentially equal, 5-11 mm long

                                                 24 Corollas white with a white or purple throat (I. aquatica) or yellow or purple throat (I. imperati); larger leaves either hastate (I. aquatica) or 3-7-lobed (I. imperati).

                                                      26 Leaves hastate, the apex acute to acuminate; [plant aquatic]

                                                      26 Leaves (the larger) 3-7-lobed, the lobe apices rounded, truncate, or emarginate; [plant of dunes and beaches]

                                               23 Stems erect or twining, not rooting at the nodes (except sometimes in I. batatas); leaf apex acute to acuminate.

                                                        27 Corollas blue, the throat white or yellow; sepals 3-7 mm long.

                                                          28 Corollas 1.5-2.5 cm long; calyx 3-5 mm long, muricate; inflorescence axis clasped by the cordate leaf base

                                                          28 Corollas 3.5-6 cm long; calyx (4-) 6-7 mm long, glabrous; inflorescence axis free

                                                        27 Corollas pink, pink-purple, or white, the throat pink or purple; sepals 4-15 mm long.

                                                            29 Leaf bases sagittate or hastate.

                                                              30 Leaves glabrous; sepals oval, 8-9 mm long, apex obtuse to rounded, mucronulate, coriaceous, glabrous; corollas 5-6 cm long; [widespread in the outer Coastal Plain from ne. NC south to s. FL, west to s. TX, and scattered elsewhere as an introduction]

                                                              30 Leaves pubescent; sepals 5-8 mm long, ovate-lanceolate to oblong-lanceolate or lanceolate, apex acuminate, mucronate, ciliate; corollas 3-4 cm long; [s. FL]

                                                            29 Leaf bases cordate (or rarely cuneate or truncate in some species).

                                                                 31 Sepals (especially the outer) with strongly raised-ribbed venation; seeds pilose with brownish hairs ca. 5 mm long.

                                                                   32 Leaf blades cordate at base, ovate (and often pandurate) in shape, 1-2.5× as long as wide; [widespread in our region]

                                                                   32 Leaf blades broadly cuneate, truncate or shallowly cordate at base, 2-4× as long as wide; [KS, OK, and TX]

                                                                 31 Sepals with venation inconspicuous and planar or only the midvein obvious; seeds glabrous, puberulent, or lanose.

                                                                     33 Corollas 5-9 cm long, ca. 6 cm in diameter (across the limb); seeds ca. 8 mm long; [s. TX]

                                                                     33 Corollas 1-4.5 cm long, 1-4.5 cm in diameter (across the limb); seeds 2.8-7 mm long; [collectively widespread in our region].

                                                                       34 Sepals 4-6 mm long; seeds with surface minutely tomentulose, densely pilose on the angles; capsules conical, 7-12 mm long

                                                                       34 Sepals 6-15 mm long; seeds with surface glabrous, the angles sometimes short pubescent; capsules subglobose, 4-8 mm long; [Batatas Clade].

                                                                         35 Corollas 2-4.5 cm long, 2.2-3.2 cm in diameter across the limb, at least partly pink to lavender (or entirely white in I. batatas); seeds shortly pubescent on the angles.

                                                                           36 Sepals unequal in length, oblong-ovate, with acute to caudate apices; leaves mostly 10-15 cm wide; [cultivated, rarely persistent]

                                                                           36 Sepals more-or-less equal in length, oblong-lanceolate, with acuminate apices; leaves 2-5 cm wide; [native, widespread in the southern portion of our region, especially in the Coastal Plain].

                                                                              37 Sepals hispid-pilose or at least ciliate; leaf blades and stems hispid-pilose to sparsely pilose, rarely glabrous

                                                                              37 Sepals glabrous; leaf blades and stems glabrous

                                                                         35 Corollas 0.6-2.5 (-3.0) cm long, 1-2 cm in diameter across the limb, white or lavender; seeds glabrous.

                                                                                38 Corollas white; seeds 5-6 mm long

                                                                                38 Corollas pink or lavender; seeds 2.8-3.6 mm long.

                                                                                  39 Sepals 5-7 mm long, oblong

                                                                                  39 Sepals 8-14 mm long, lanceolate.

                                                                                    40 Sepals mostly 8-11 mm long, subequal; corolla 2-2.5 cm in diameter across the limb