2. Carya cordiformis (Wangenh.) K. Koch (bitternut hickory, pignut hickory)

Pl. 430 g, h; Map 1924

Plants trees to 35 m tall (to 50 m elsewhere). Bark gray to brownish gray, smooth or shallowly furrowed and exfoliating in small flakes. Twigs 3–4 mm thick, tan to light brown, the terminal bud 4–11 mm long, yellow or tan, the bud scales meeting at their margins and not or scarcely overlapping, the bractlets around the axillary buds free (but usually completely hidden by dense peltate scales). Leaves with the petiole and rachis pubescent (sometimes becoming nearly glabrous toward the petiole base), with (5)7 or 9 leaflets. Leaflets 4–18 cm long, 1–8 cm wide, lanceolate to oblanceolate or obovate, straight or weakly arched (appearing slightly asymmetrically tapered), the margins finely to coarsely toothed, glabrous or with scattered hairs, the upper surface glabrous or with scattered, small, circular, whitish to brownish, peltate scales, the undersurface with scattered to relatively dense, branched (the branches appearing fasciculate) hairs, sometimes mainly along the veins or becoming nearly glabrous with age, and also with scattered, small, circular, pale yellow to brownish, peltate scales. Staminate catkins noticeably stalked to nearly sessile. Fruits 2–3 cm long, 2–3 cm wide, globose to somewhat ellipsoid, not flattened, with low wings along the 4 sutures, the husk 1–2 mm thick, splitting 50–80% of its length, with small golden yellow scales that wear off with age. Nut not or only slightly flattened, the shell less than 1 mm thick. Seed bitter. 2n=32. April–May.

Scattered to common nearly throughout the state (eastern U.S. west to Minnesota and Texas; Canada). Banks of streams and rivers, margins of ponds, lakes, sinkhole ponds, oxbows, and sloughs, bottomland forests, bases of bluffs, and less commonly mesic upland forests; also roadsides.

Plants with unusually broad leaflets (5 cm or broader) have been called f. latifolia (Sarg.) Steyerm.