1 Leaves unlobed, to 9 cm long; plants 2-20 dm tall.

  2 Leaf margins entire; petals white, with a red blaze at the base

  2 Leaf margins toothed; petals yellow, cream, or orangy (or white and not red-blazed in S. abutilifolia).

    3 Plants procumbent or trailing herbs, the stems 1-6 (-10) dm long.

      4 Leaf blades 3-5 cm long, 1-1.2× as long as wide

      4 Leaf blades 0.4-1.5 cm long, 1.5-3× as long as wide.

        5 Petals white; leaves distributed evenly along stems; leaf blades crenate to base

        5 Petals salmon, red-orange, or yellowish; leaves crowded near stem tip; leaf blades dentate only near apex

    3 Plants erect or ascending herbs, subshrubs, or shrubs, the stems 4-20 dm tall.

          6 Mericarps, styles, and stigmas 5; leaves usually truncate to subcordate or cordate at the base.

             7 Stems and petioles minutely stellate-pubescent, the hairs to 0.5 mm long (use 10× or greater magnification); [widespread in our region]

             7 Stems and petioles either glandular-viscid or with simple hairs 1-3 mm long; [s. FL, s. AL]

               8 Stems glandular-viscid; petals white or yellow-orange without a darker base, not fading rose-pink; calyces usually glandular, the lobes triangular, acute to short-acuminate (not beaked in bud)

               8 Stems not glandular-viscid; petals yellowish to orange or salmon, usually with a dark orange or reddish base, fading rose-pink; calyces setose, the lobes trullate, attenuate-aristate (beaked in bud)

          6 Mericarps, styles, and stigmas 7-14; leaves usually cuneate to rounded (cordate to subcordate in S. cordifolia) at the base.

                 9 Leaves and branches arrayed distichously.

                   10 Mericarps 7-8; mericarp spines ca. 2 mm long; inflorescences usually axillary glomerules (the flowers sometimes solitary or paired); calyx 5-6 mm long; staminal column glabrous

                   10 Mericarps (7-) 8-12; mericarp spines 0.5-1 mm long; inflorescences axillary, the flowers 1-2; calyx 6-8 mm long; staminal column hairy (sometimes glabrous)

                 9 Leaves and branches arrayed spirally.

                     11 Leaves cordate to subcordate at the base; petiole (5-) 10-25 mm long

                       12 Leaf blades velvety-tomentose, 1-2× as long as wide; inflorescences axillary, usually of corymbs or panicles, sometimes solitary flowers; fruits 6-7 mm in diameter; mericarp spines to 2 mm long

                       12 Leaf blades not velvety, usually 4-6× as long as wide; inflorescences axillary, of a solitary flower; fruits 5-6 mm in diameter; mericarp spines to 1 mm long

                     11 Leaves cuneate to rounded at the base; petiole 2-10 (-40) mm long.

                          13 Leaf blade margins entire towards base, dentate or serrate only nearer the tip, the entire portion usually 1/3 to 1/2 the length of the leaf.

                            14 Pedicels 0.4-1.2 cm long; leaf blades lanceolate-elliptic to round, 1.5-5 cm long

                            14 Pedicels 0.5-4 (-16) cm long; leaf blades rhombic, subrhombic, or elliptic, 2.5-9 cm long.

                              15 Petals yellow; stem hairs to 0.1 mm long; pedicels (1-) 3-4 cm long

                              15 Petals cream or pale yellow with a reddish spot at the base; stem hairs to 0.5 mm long; pedicels to 2 cm long

                          13 Leaf blade margins crenulate, serrate, or dentate to the base.

                                16 Stipules 1.5-2× as long as the petiole, linear; leaf blade narrowly rhombo-elliptic, 4-6× as long as wide, glabrate above; seeds pubescent apically and ventro-apically; peduncles 0.5-2 (-3) cm long, 0.5-0.75× as long as the subtending leaf, articulated ca. 0.5-1 cm below the calyx; [endemic to peninsular Florida]

                                16 Stipules 0.5-1× as long as the petiole, falcate or subulate, not linear; leaf blade linear, lance-linear to narrowly elliptic, (3-) 4-21× as long as wide, but if (3-) 4-6× as long as wide then the leaves crenulate-serrate and the peduncle not articulated; seeds glabrous to apically pubescent, usually ventro-apically glabrous; peduncle 0.5-1.25× as long as the subtending leaf, but if articulated then 0.75-1.25× as long; [collectively more widespread].

                                  17 Peduncles 2-6 cm long, approximately equal or somewhat exceeding the subtending leaf, articulated 1-2 cm below the calyx with the articulation becoming most prominent on mature, fruiting peduncles; flowers strictly axillary; [of LA westwards]

                                  17 Peduncles 0.5-4.5 cm long, shorter than the subtending leaf (rarely exceeding it in S. elliottii), not articulated; flowers axillary to aggregated apically; [collectively more widespread].

                                    18 Leaf margins crenulate-serrate, more densely so toward apex; lower surface venation prominently greenish yellow with venation inconspicuous on upper surface; calyx lobes apically acuminate to weakly caudate, tricolorous, yellowish to greenish cream at base, becoming green and then darker green distally

                                    18 Leaf margins evenly serrate; venation not conspicuous; calyx lobes apically acute to weakly acuminate; essentially monochrome, green at base.

                                       19 Calyx stellate-pubescent, usually villous-hirsute at base and along veins; flowers axillary to apically congested; leaves linear to narrowly elliptic, purplish along margins or not, glabrate to stellate and simple-pubescent above; plants to 1 m tall; [widespread in our area, south to ne. and Panhandle FL]

                                       19 Calyx stellate-pubescent, villous hairs absent; flowers axillary; leaves linear, usually purplish along margins, glabrate above; plants to 0.5 m tall; [peninsular Florida]