Juglans major (literally, the larger walnut), also known as Arizona walnut, is a walnut tree which grows to 50 ft with a DBH of up to 2 ft at elevations of 1000–7000 ft in Texas, Oklahoma, New Mexico, Arizona, and Utah. It also occurs in Mexico as far south as Guerrero. Common names include Arizona black walnut (as it belongs to the "black walnuts" section Juglans sect. Rhysocaryon), and the Spanish name nogal cimarrón (cimarron walnut).

Description

In moister areas, the tree features a single, stout trunk; there are usually several slender trunks in drier situations. The 8–14 in long pinnately compound leaves bear 9–15 lanceolate leaflets, .75-1.25 in wide by 2-4 in long. The small nut has a thick shell with deep grooves enclosing an oily, edible seed. J. major grows primarily in canyons or riparian areas, near springs, and other areas with shallow groundwater. Where the range of J. major overlaps that of J. microcarpa, the two interbreed, producing many intermediate forms.