About Eysenhardtia orthocarpa (A.Gray) S.Watson
Eysenhardtia orthocarpa is a small flowering kidneywood tree in the legume family Fabaceae. This species is native to the northern Sierra Madre Occidental cordillera in eastern Sonora, Mexico, and also occurs in central Sonora. Its range extends northward into southeastern Arizona and the extreme southwest bootheel region of New Mexico, covering the entire Madrean Sky Islands, the northern sky island region of the cordillera. In central Sonora, Eysenhardtia orthocarpa grows in the eastern Sonoran Desert, which extends into southeastern Arizona. The species does not grow in the hotter, lower elevation desert areas of west-northwestern Arizona. It also avoids the hot Gran Desierto de Altar located to the northwest on the eastern shore of the Gulf of California in Sonora.
