Juglans californica, also known as Southern California black walnut or California walnut, is a species of walnut tree native to California, Arizona, and northern Mexico. There are many synonyms for this species, including Juglans californica var. californica, Juglans californica var. hindsii, and Juglans californica subsp. californica. Other common names for this tree include Arizona black walnut, southern California walnut, and just plain black walnut. This tree is highly valued for its wood, which is often used in furniture-making, but it is also a popular ornamental tree due to its striking foliage and ability to thrive in hot, dry climates.