About Pelecyphora aselliformis C.Ehrenb.
Pelecyphora aselliformis C.Ehrenb. produces grayish green stems that are globose, spherical, or flattened-spherical, along with fleshy roots. Mature stems are 2 to 7 centimeters in diameter and around 12 centimeters high. The species has distinctive hatchet-shaped tubercles, which measure 2 to 4 millimeters high, 5 to 9 millimeters long, and 1 to 2.5 millimeters wide. The outer portion of each tubercle is flattened, and its overall outline is elliptical. The areoles are covered in wool, and bear 40 to 60 stiff, whitish spines that arrange in a prominent comb-like pattern. These spines range from 0.7 to 4 millimeters in length. Magenta flowers grow at the stem apex, emerging from the wool of young areoles, and reach diameters of 1.3 to 3.5 centimeters. This species grows very slowly, and does not produce flowers until it is many years old.
Pelecyphora aselliformis is widespread in the Mexican state of San Luis Potosí. It grows on low hills and flat plains, at elevations between 1800 and 2400 meters. It inhabits nutrient-rich dark soils and limestone rock, and its entire range covers an area no larger than 500 square kilometers.
