Juglandaceae
Deciduous, monoecious trees, occasionally shrubs. Lvs alternate, imparipinnate, exstipulate. ♂ fls numerous, usually in pendulous catkins, bracteate; bracteoles usually 2; perianth of calyx only, (1)-3-6-lobed, usually adnate to bracteoles; stamens 3-40, in 2 or more series; filaments short. ♀ fls few, sessile on the axis; bract and bracteoles 2; perianth 4-lobed, ± adnate to ovary; ovary inferior, 1-celled or incompletely 2-4-celled. Ovule 1, erect, basal. Style 2-fid, with stigmatic surface on inner face of branches. Fr. either a drupe with soft exocarp and endocarp hard, intrusive and 2-4-celled at base, or, less commonly, a nut (sometimes winged) and often adnate to enlarged bract and bracteoles. Seed non-endospermic, 2-4-lobed; cotyledons often very contorted and oily.
6-8 genera, 50-60 spp., nearly all in N. temperate regions, especially E. Asia and E. North America, a few in subtropical and tropical S.E. Asia and the Andes S. to Argentina.
In addition to Juglans, the N. American genus Carya Nutt., hickories, pecans, and pignuts, is becoming increasingly common in cultivation. Although generally resembling walnuts, Carya spp. have a solid pith and the fr. husk dehisces. Another genus sometimes cultivated is the Asiatic Pterocarya Kunth, wingnuts; as in Juglans spp., the pith is lamellate but the racemes of small winged nuts immediately distinguish them. Trees of Pterocarya fraxinifolia (Lam.) Spach are occasionally grown and spread by suckering profusely, but the commoner P. stenoptera DC. does not.
