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| 1 Flowers with 5 petals, 2 fused to form the keel (papilionaceous); corolla rose, yellow, orange, red, pink, or white; [subfamily Faboideae]. |
| ..2 Lianas climbing by twining; stamens 9, monadelphous |
| ..2 Shrubs; stamens 10, diadelphous (9 and 1). |
| ....3 Leaflet pairs 10-25; [widespread] |
| ....3 Leaflet pairs 4-6. |
| ......4 Leaflets 10-25 mm long; corolla 15-20 mm long, yellow; [non-native cultivated and sparingly established] |
| ......4 Leaflets 3-11 mm long; corolla 8-11 mm long, pink or white; [native, s. TX] |
| 1 Flowers with 5 or 3 petals, all distinct (caesalpinaceous); corolla yellow, orange, red, or pink; [subfamily Detarioideae or Caesalpinioid clade]. |
| ........5 Large tree; sepals 4; petals 3; functional stamens 3; [subfamily Detarioideae] |
| ........5 Shrub or small tree (< 5 m tall); sepals 5, petals 5, functional stamens 6-10; [Caesalpinoid clade]. |
| ..........6 Trees; filaments of the 3 lower stamens curved; petiolar gland absent; [introduced in s. FL] |
| ..........6 Shrubs or trees; filaments of all stamens straight; petiolar and/or rachis gland(s) present or absent; [collectively more widespread]. |
| ............ 7 Leaflets 0.6-1.0 cm long, coriaceous, the venation raised-reticulate below; functional stamens 10; [s. TX] |
| ............ 7 Leaflets 1.5-10.5 cm long, herbaceous; functional stamens 6-7 (10 in S. surattensis); [collectively more widespread, but especially FL and s. TX] |