The buckhorn cholla (Cylindropuntia acanthocarpa
) is an open and spreading woody cactus, up to 1 m tall. The gray-green stems, also called "joints", are cylindrical, 5-30 cm long and 17-20 mm in diameter with tubercles or nodules. Each tubercle has a cluster of stiff spines, which are covered with loose papery sheaths. The flowers are up to 5 cm long and range from yellow to purple-red with shades in between. The fruits are obovoid, dry, shriveled and spiny and drop off later in the season. The seeds are light yellowish to gray-brown, 3.5 to 4 mm. long.
Varieties of C. acanthocarpa
(var. acanthocarpa, var. coloradensis, var. major and var. thornberi) are found in Arizona, California, Nevada and Utah; in Arizona, all of the varieties are protected plants.