Those whitish markings on the leaf veins and rounded leaf tips are typical of Desmodium perplexum.

Love this group! Hang around long enough and all those old "unidentifieds" will move out of that category. Found this a few years back (ok, maybe a lot of years now) on a hike, took some pictures, and always meant to try to find out its ID but never did. Thanks!

FataMorgana

Arkansas has lots of Desmodium species, and that's one of my favorites. It isn't particularly showy, but has interesting foliage and pink corollas with bright green spots at the base. D. perplexum is a common native species in the eastern half of the US.

Also, Desmodium species are host plants for theSilver-spotted Skipper, Epargyreus clarus. :-)