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..2 Pinnae pairs 6-14 (-17) per leaf; new growth terminal on existing branches; [of s. TX]
..2 Pinnae pairs 4-8 per leaf; new growth basal from the woody taproot; [of s. FL]
......4 Fruiting peduncles 2-6.2 cm long; fruits dark brown at maturity with only slightly raised reticulate venation on the valves, apically obtuse; leaflets abaxially pubescent; sterile flowers present at the base of the inflorescence
......4 Fruiting peduncles 7-14 cm long; fruits light brown at maturity with conspicuous raised reticulate venation on the valves, apically acute; leaflets abaxially glabrous or glaucous; sterile flowers absent
........5 Young stems velutinous with spreading white hairs of variable lengths, on the ridges and between them (though less densely than on the ridges)
..........6 Pinna pairs (5-) 7-18 per leaf; stamens 5; legume 15-25 (-32) mm long, 4.5-7.0 mm wide, 3-4× as long as wide, strongly curved; [widespread]
............ 7 Pinna pairs 4-7 (-9) per leaf; stamens 5; legume 40-74 mm long, 2.5-3.0 mm wide, > 18× as long as wide
............ ..8 Nectary between lowest pair of pinnae 0.3-1.0 (-1.2) mm in diameter; legumes dehiscent along both sutures but not curling longitudinally and the inner surface of each valve therefore remaining concave; taproot brown, cylindrical (to 50 cm long × 2 cm in diameter)
............ ..8 Nectary between lowest pair of pinnae 0.8-3.0 mm in diameter; legumes dehiscent along both sutures, the sutural ridges curling longitudinally over the valves after dehiscence and causing the inner surface of each valve to be slightly convex; taproot red, napiform (turnip-like) (to 40 cm long × 2.5 cm in diameter at the thickest point)
............ ....9 Leaflet pairs 7-12 per pinna; pinna pairs 2-4 per leaf; flowering/fruiting heads on peduncles 6-20 mm long; nectary between lowest pair of pinnae 0.8-2.0 mm in diameter.
............ ....9 Leaflet pairs 19-38 per pinna; pinna pairs 1-2 per leaf; flowering/fruiting heads sessile or on peduncles to 5 mm long; nectary between lowest pair of pinnae 1.4-3.0 mm in diameter