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1 Loment segments 3-5.5 mm long, nearly symmetrical along the axis of the loment (the isthmi more or less equal above and below, thus each segment diamond-shaped, rounded-diamond-shaped, or essentially elliptical).
..2 Leaflet undersurfaces with hooked hairs, mainly or only on the veins; loment segments 4-5.5 mm long; perennial; [OH, IN, IL, AR, OK, and TX plains northward]
..2 Leaflet undersurcaes villous, strigose, or also with hooked hairs; loment segments 3-3.5 mm long; annual from a taproot; [NC south to s. FL, west to AR and TX, mainly Coastal Plain]
1 Loment segments 5-11 mm long, asymmetrical along the axis of the loment (the isthmi deeper below than above, thus each segment triangular, rounded-triangular, or semi-circular).
....3 Leaflets with conspicuous pale variegation along the midvein; corollas 7-8 mm long, white ('fading' light pink); [Crosstimbers and Blackland Prairies of TX and OK]