1 Leaves predominantly basal.

  2 Upper corolla-lip strongly arched; leaves serrate

  2 Upper corolla-lip straight (or only slightly curved, not strongly arching); leaves lobed or toothed

    3 Veins of the 3 upper calyx lobes parallel, the lobes themselves minute and widely-spaced (> 1 mm between the 2 lateral teeth), separated by flattish sinuses; basal leaves lobed; [native, though weedy, common throughout our area]

    3 Veins of the 3 upper calyx lobes converging, the lobes themselves minute and spaced within a distance of 1 mm; basal leaves lobed or toothed; cauline leaves toothed (rarely lobed); [exotic weed, rarely naturalized in our area].

1 Leaves predominantly cauline, not lobed.

      4 Leaves rhombic-ovate (ovate-lanceolate in the waif S. hispanica), the bases cordate, subcordate, truncate, or broadly cuneate.

        5 Petiole not clearly differentiated from the leaf blade (leaf tissue decurrent on the petiole for most or all its length, appearing winged); corolla blue.

          6 Calyx < 5 mm long (ca. 2 mm); plants < 1 m tall; leaves 2-5 cm long and 1-3 cm wide; [c. FL (Orange County) southward]

          6 Calyx lobes > 5 mm long; plants 1.4-2.0 m tall; leaves 6-12 cm long and 3.0-6.5 cm wide; [n. FL north and westward]

             7 Leaves with cuneate bases extending into a winged petiole; plants typically with both terminal and axillary inflorescences; corolla 7-12 mm long; flowering Aug-Oct

             7 Leaves with abruptly truncate bases into a winged petiole; plants typically with a single terminal inflorescence; corolla 10-17 mm long; flowering Apr-May

        5 Petiole clearly differentiated from the leaf blade (not appearing winged); corolla blue, white, or scarlet.

               8 Corolla scarlet; larger leaves 3-6.5 cm long; [native]

               8 Corolla blue or whitish; leaves 5-20 cm long; [natives or non-natives]

                 9 Calyx lobes acute, obtuse, or rounded; [collectively widespread].

                   10 Leaves ovate-lanceolate

                   10 Leaves rhombic-ovate.

                     11 Leaves 1.5-4.5 cm long; plants annual, to 0.5 m tall; calyx with extensive capitate-glandular pubescence; [native, c. and s. FL].

                       12 Calyx 4.5-7 mm long (mature 5.5-8.0 mm long); corolla blue to violet; leaf blades 1.5-4.5 cm long, deltoid, the abaxial surface glabrous, pubescent on the veins

                       12 Calyx 3.5-4 mm long (mature 5.0-5.5 mm long); corolla white to lavender; leaf blades 1.0-2.5 cm long, ovate, the abaxial surface densely pubescent

                     11 Leaves 5.0-20 cm long; plants biennial or perennial, to ca. 1 m tall; [waifs, NC and MO northward].

                          13 Upper calyx lip > ½× as long as the calyx tube; flowers 4-12 per node; leaves (8-) 12-20 cm long

                          13 Upper calyx lip < 1/3× as long as the calyx tube; flowers 12-30 per node; leaves 5-10 cm long

      4 Leaves lanceolate, linear, or narrowly elliptic, the bases cuneate to attenuate.

                            14 Shrub, distinctly woody; leaves linear, strongly revolute

                            14 Herb, not woody; leaves lanceolate to narrowly elliptic, not revolute

                              15 Leaves canescent, gray (sometimes sparsely so in S. farinacea, which has densely canescent calyx lobes).

                                16 Calyx lobes densely canescent; leaves linear to elliptic, sometimes curved upwards; [native of limestone uplands w. of MS river, waif in n. FL]

                                16 Calyx lobes pubescent, but not densely canescent; leaves lanceolate to elliptic, flat; [introduced, rarely persistent from cultivation in gardens]

                              15 Leaves puberulent, green; [native, of dry woodlands from sc. NC southward and westward].

                                  17 Flowers 2 (-4) per node; corolla 8-12 mm long; annual

                                  17 Flowers 6-10 flowers per node; corolla > 13 mm long; perennial.

                                    18 Stem usually with sparse, antrorse or somewhat spreading pubescence; calyx with antrorse hairs limited to major veins; flowers of mature inflorescences spaced out, most internodes elongate and ranging up to 25 (-34) mm; [Atlantic and Gulf Coastal Plain and adjacent piedmont, from south-central NC to central FL to southeast LA]

                                    18 Stem usually with dense, retrorse pubescence; calyx with dense antrorse pubescence; flowers of mature inflorescences densely arranged, internodes between flowers very short, only the lowermost 1-3 internodes elongate and ranging up to 12 (-17) mm; [inland and prairie sites, ranging from IL, IA, NE, and e. CO south to nw. GA, n. AL, ne. MS, LA, and se. and c. TX]