1a. Carpinus caroliniana subsp. caroliniana
Trees , to 8 m; trunks short, crooked, shallowly fluted, crowns open, spreading. Bark steel gray or brownish gray, smooth to somewhat roughened. Winter buds containing inflorescences squarish in cross section, 3--4 mm. Leaf blade narrowly ovate to oblong-ovate, 3--8.5(--12) × 3--6 cm, base narrowly rounded to cordate, margins doubly serrate, apex acute or obtuse; surfaces abaxially slightly to moderately pubescent, especially on major veins, without small dark glands. Infructescences 2.5--7 cm; bracts relatively uncrowded, 2--3 × 1.4--2.3 cm, lobes narrow, elongate, apex acute, obtuse, or rounded.
Flowering late spring. Stream banks, flood plains, and moist slopes, frequently in understory; 0--200 m; Ala., Ark., Del., Fla., Ga., Ill., Ky., La., Md., Miss., Mo., N.J., N.C., Okla., S.C., Tenn., Tex., Va.
Carpinus caroliniana subsp. caroliniana is characteristic of the southern Atlantic and Gulf of Mexico coastal plains and also extends northward in the Mississippi Embayment. It differs from C . caroliniana subsp. virginiana in its smaller, more ovate, more acute-tipped leaves that have finer secondary teeth and lack conspicuous dark glands abaxially.