About Pelecyphora tuberculosa (Engelm.) D.Aquino & Dan.Sanchez
This species, previously described as Escobaria tuberculosa, grows singly or in clusters and is highly variable in form. Its cylindrical to egg-shaped shoots grow 5 to 12 centimeters tall, with diameters of 2.5 to 7 centimeters. The warts on the shoots can reach up to 10 millimeters in length, and become hard and persistent as they mature. It has four to eight straight, yellow central spines that measure 1 to 2 centimeters long, with pink or red tips; one of these central spines is thicker than the others. It also has approximately 20 to 30 straight, spreading marginal spines that can be yellow, white, or gray, and reach up to 1.2 centimeters long. The fragrant flowers are pink, open widely, and measure 2 to 3 centimeters long and 2 to 3 centimeters across. The elongated fruits are usually red, and grow 1.2 to 2 centimeters long. Escobaria tuberculosa is fairly widespread in the United States, where it occurs in the states of New Mexico and Texas, and in Mexico it is found in the states of Chihuahua, Durango, Coahuila, and Nuevo León. It only grows on igneous rocks.
