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| 1 Leaflets 1; [e. TX southwestwards] |
| 1 Leaflets 3-9; [collectively widespread in our region]. |
| ..2 Leaflets 5-9. |
| ....3 Leaflets 5-9, leaflets in a conventionally pinnate arrangement; flowers white, 3-11 in a terminal inflorescence; [Coastal Plain of FL, GA, and SC] |
| ....3 Leaflets mostly 5 (3-7 per leaf, most on a plant 5), the 4 non-terminal leaflets at a single node at the summit of the petiole; flowers pink, solitary and axillary; [TX] |
| ..2 Leaflets 3; flowers white, pink, red, or purple. |
| ......4 Stems erect (not prostrate, trailing, or twining), with 4-6 (-8) leaves, usually alternately bent at nodes; inflorescence subsessile, 1-6-flowered |
| ......4 Stems prostrate, trailing, or twining, with numerous leaves (except in depauperate plants), not bent at nodes; inflorescence pedunculate, 1-flowered if sessile or subsessile. |
| ........5 Stems climbing or sprawling, twining. |
| ..........6 Corollas 11-14 (-15) mm; stems loosely strigose with short, loosely appressed, retrorse hairs, strongly lignescent |
| ..........6 Corollas 7-11 mm; stems strigose to hirsute or hirsute-pilose, herbaceous to weakly lignescent or (G. striata) strongly lignescent. |
| ............ 7 Banner striped with white lines; [c. and s. FL peninsula, coastal and near-coastal] |
| ............ 7 Banner not striped; [collectively widespread]. |
| ............ ..8 Fruits falcate; flowers 1-5, solitary and pedicellate or 2-5 on an inflorescence axis 1-4 (-40) mm long; [TX] |
| ............ ..8 Fruits straight; flowers 1-8 (-16), solitary and pedicellate or 2-8 (-16) on an inflorescence axis 10–150(–280) mm long; [collectively widespread]. |
| ............ ....9 Stems strigose with antrorse hairs; leaflets linear-oblong to narrowly oblong or narrowly elliptic, 2-4 (-6) mm wide; [s. FL only] |
| ............ ....9 Stems strigose to hirsute or hirsute-villous with spreading-deflexed to retrorse hairs; leaflets oblong to elliptic or lanceolate, 5-21 (-25) mm wide; [more widely distributed]. |
| ............ ......10 Leaflets narrowly oblong to oblong-lanceolate, 6-14 mm wide; fruits 35-65 mm long, seeds 12-15 per fruit; [TX] |
| ............ ......10 Leaflets various (see below), 5-21 (-25) mm wide; fruits 20-52 mm long; seeds 5-11 per fruit; [collectively widespread]. |
............ ........11 Leaflets mostly elliptic to broadly elliptic, (5-) 10-21 (-25) mm wide, usually widest at the midpoint; stems moderately to densely hirsute to hirsute-villous with spreading-deflexed hairs; corollas 7-10 mm; leaflets thick in texture, not glaucous below |
| ............ ........11 Leaflets mostly ovate to lanceolate, 5-15 (-17) mm wide, widest below the midpoint; stems moderately to sparsely strigose with tightly to loosely appressed, retrorse hairs, sometimes glabrate; corollas 9-14 mm; leaflets thin in texture, usually glaucous below |
| ........5 Stems procumbent at least proximally and variously twining, weakly twining, or not twining towards the tip. |
| ............ ..........12 Stems gray retrorse-strigose; leaflets roundish, 1-1.3× as long as wide; stems 'rooting' at nodes, producing rhizomes; inflorescences of 2 types: 1) aerial inflorescences with chasmogamous flowers, and 2) single, subterranean, cleistogamous flowers that develop into 1-seeded legumes; [TX and southwards] |
| ............ ..........12 Stems variously hairy to glabrous, but not gray retrorse-strigose; leaflets elongate, > 1.5× as long as wide; stems not rooting at nodes; inflorescences all aerial with chasmogamous flowers; [LA and eastwards] |
| ............ ............ 13 Calyx lobes brown to reddish brown on inner surface when dry; corollas distinctly dark reddish when dry, persisting after withering, sometimes still present when fruit is mature |
| ............ ............ 13 Calyx lobes greenish-yellow to tan on inner surface when dry; corollas light whitish to blue, pinkish, or purplish when dry, not persisting after anthesis. |
| ............ ............ ..14 Leaflets subcoriaceous to coriaceous, venation raised on both surfaces. |
| ............ ............ ....15 Leaflets mostly linear-oblong or narrowly oblong, 2-8 (-11) mm wide; [c. and s. peninsular FL only] |
| ............ ............ ....15 Leaflets elliptic, oblanceolate-elliptic, oblong-elliptic, elliptic-lanceolate, or broadly lanceolate, (4-) 7-25 (-32) mm wide; [mainly Coastal Plain, s. NJ south to s. FL, west to s. MS] |
| ............ ............ ......16 Several to most internodes (especially those toward the base) longer than the largest leaflet of adjacent nodes, hairs on the stem 0.1-0.8 mm long; leaflets (4-) 10-25 (-32) mm wide; flowers (3-) 5-15 (-25), rarely 1-2 |
| ............ ............ ......16 Internodes only a little longer to usually shorter than the largest leaflet of adjacent nodes, hairs on stems 0.05-0.25 mm long; leaflets (4-) 7-10 (-18) mm wide; flowers solitary and axillary or 2-4 |
| ............ ............ ..14 Leaflets herbaceous, venation not raised. |
| ............ ............ ........17 Leaflets (14-) 20-55 × (10-) 15-35 mm; flowers 5-12 (-25) |
| ............ ............ ........17 Leaflets 8-30 × 5-20 mm; flowers solitary and axillary or 2-6. |
| ............ ............ ..........18 Inflorescence axis 10-20 mm; calyces 3-4 mm; corollas 6-7 mm; [Panhandle FL and adjacent s. AL] |
| ............ ............ ..........18 Inflorescence axis (5-) 20-60 (-90) mm; calyces 6-7 mm; corollas 12-15 mm; [s. FL] |