1 Plants decumbent, rooting at the nodes, < 4 dm tall; calyx tube densely short-pubescent and also pilose with longer glandular hairs; [Cumberland Plateau of KY and TN]

1 Plants upright, 3-15 dm tall; calyx tube glabrous, minutely and inconspicuously puberulent, or more densely puberulent, pubescent, or villous; [Coastal Plain of FL, s. AL, and s. MS]

..2 Leaves oblanceolate, slightly revolute, the leaf undersurface mostly visible and showing 1-4 raised lateral veins; [Putnam County, FL].

....3 Calyx 8.5-11 mm long, the upper lobe 3.6-4.4 mm long; cyme 1-5-flowered; unicellular hairs of the lower leaf surface thin-walled, collapsing and flattened in drying; [ec. Putnam County, FL]

....3 Calyx 7-8.5 mm long, the upper lobe 1.8-3.5 mm long; cyme 3-7-flowered; unicellular hairs of the lower leaf surface thick-walled, terete to conical, unchanged in drying; [nw. Putnam County, FL]

..2 Leaves either linear and strongly revolute such that essentially only the midvein is visible on the undersurface or linear to narrowly oblanceolate, slightly to strongly revolute, some leaf surface sometimes showing on the leaf undersurface, but lacking raised lateral veins; [collectively more widespread].

......4 Leaves green or gray-pubescent above; midrib on lower leaf surface glabrous or glabrate, contrasting with the more densely pubescent lower leaf surface.

........5 Leaves densely gray-pubescent above; calyx tube densely short-pubescent; leaves 7-10 mm long, 1.2 mm wide; [FL peninsula, mainly along the east coast]

......4 Leaves densely gray-pubescent above and below; midrib on lower leaf surface densely gray-pubescent to gray-pilose.

..........6 Leaves 6-10 (-13) mm long; mericarps 1.0-1.2 mm long at maturity; [central peninsular FL]

..........6 Leaves 7-20 mm long; mericarps 0.8-1.0 mm long at maturity; [East Gulf Coastal Plain of c. and w. Panhandle FL and adjacent s. AL and s. MS]