Carpinus caroliniana consists of two rather well-marked geographical races, treated here as subspecies. These hybridize or intergrade in a band extending from Long Island along the Atlantic coast through coastal Virginia and North Carolina, and then westward in northern South Carolina, Georgia, Alabama, Mississippi, and Louisiana. Plants with intermediate features are also found throughout the highlands of Missouri and Arkansas. J. J. Furlow (1987b) has described the variation of this complex in detail.
Native Americans used Carpinus caroliniana medicinally to treat flux, navel yellowness, cloudy urine, Italian itch, consumption, diarrhea, and constipation, as an astringent, a tonic, and a wash, and to facilitate childbirth (D. E. Moerman 1986; no subspecies specified).