Juglans illinoinensis Wangenheim, Beytr. Teut. Forstwiss. 54. 1787; Hicoria olivaeformis (Michaux) Nuttall; H. pecan (Marshall) Britton; Juglans olivaeformis Michaux; J. pecan Marshall.

Trees to 50 m tall. Terminal buds with 4 or more false-valved scales, yellowish brown. Leaves 25-35 cm; petiole 4-8 cm, glabrous or glabrescent; rachis generally glabrous or glabrescent; leaflets (7 or)9-13(-17), lateral ones shortly petiolulate or sessile, blade ovate-lanceolate to elliptic-lanceolate or long elliptic, 7-18 × 2.5-4 cm, with scattered, peltate scales, abaxially pubescent or glabrescent, base oblique, broadly cuneate or subrounded, apex acuminate; terminal petiolule 5-25 mm. Male spikes 8-14 cm; peduncle nearly absent. Anthers sparsely pilose. Nuts ovoid-ellipsoid, 3-5 × 2-3 cm; husk without prominent wings; shell without longitudinal ridges, ca. 1 mm thick, 2-chambered at base, lacunae present. Fl. May, fr. Sep-Nov. 2n = 32, rarely 64.

Grown extensively in China for its edible nuts.

Cultivated. Fujian, Hebei, Henan, Hunan, Jiangsu, Jiangxi [native to United States]