Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
..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]
....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]
......4 Corolla 6-7 mm long; loment with 2-4 segments, each 5-7 mm long; lower leaves often 1-foliolate; [of se. SC and southward]
........5 Stem densely spreading pilose (at least the upper stem) and also uncinate-puberulent; loment segments 6.5-10 mm long
........5 Stem glabrous or uncinate-puberulent; loment segments 9-11 mm long