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| 1 Legume 5-11 mm in diameter. |
| ..2 Legume cylindric, 20-30 (-35) mm long, 7-9 mm in diameter, yellow-brown, leathery in texture |
| ..2 Legume globose or subspheroidal, 7-25 mm long, 5-11 mm in diameter, black, woody in texture. |
| ....3 Leaflets mostly 1-2.5 (-4) cm long |
| ....3 Leaflets 3.5-10 cm long. |
| ......4 Leaflets 3-5× as long as wide, usually < 1.5 cm wide; infructescence nodes (fruits or aborted fruits) usually 1-3; fruits broadly ellipsoid or subspheroidal, <2× as long as wide; [se. SC south through GA Coastal Plain to ne. FL] |
| ......4 Leaflets 1.7-3.2 (-5)× as long as wide, the larger typically > 2 cm wide; infructescence nodes (1-) 3-10; fruits usually ellipsoid, often > 2× as long as wide; [FL Panhandle, s. AL, and c. peninsular FL] |
| 1 Legume 8-25 mm in diameter. |
........5 Pod drying tan, thin-walled and brittle |
| ........5 Pod drying black to blackish-brown, leathery or tough. |
| ..........6 Stems puberulent (sometimes inconspicuously so) or villous. |
| ............ 7 Legume (20-) 30-40 (-50) mm long, 15-25 mm in diameter; pedicels 14-18 (-30) mm long, subtended by persistent bracts10-25 mm long and 7-10 mm wide |
| ............ ..8 Petioles of median leaves 4-10 mm long |
| ............ ..8 Petioles of median leaves 2-4 mm long. |
| ............ 7 Legume 10-35 mm long, 8-15 mm in diameter; pedicels 2-10 mm long, subtended by caducous bracts 2-10 mm long and 1-2 mm wide. |
| ............ ....9 Petiolules 2-5 mm long; stipules (some of them at least) persistent |
| ............ ....9 Petiolules 4-10 mm long; stipules caducous |
| ..........6 Stems glabrous and generally glaucous as well {B. alba, B. leucantha, B. leucophaea var. laevicaulis, B. australis var. aberrans, B. australis var. australis} |