Juglans nigra Juglans nigra Juglans nigra, the eastern black walnut, is a species of deciduous tree in the walnut family, Juglandaceae, native to eastern North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central Texas. Wild trees in the upper Ottawa Valley may be an isolated native population or may have derived from planted trees. Black walnut is an important tree commercially, as the wood is a deep brown color and easily worked. The fruits, walnuts, are cultivated for their distinctive and desirable taste. Often, trees are
Juglans californica "J. californica" grows in riparian woodlands, either in single species stands or mixed with California's oaks ("Quercus" spp.) and cottonwoods ("Populus fremontii"). "Juglans californica" can be either a large shrub with 1–5 trunks, or a small, single-trunked tree. The main trunk can fork close to the ground, making it look like two trees that have grown together, then diverged. It has thick bark, deeply channeled or furrowed at maturity. It has large, pinnately compound leaves with 11–19 lanceolate leaflets with toothed margins and no hair in the vein angles. It has a small hard nut in a shallowly grooved, thick