Boke's Button Cactus

Epithelantha bokei is a small, disc-shaped or cylindrical cactus that usually measures 2 to 5 centimeters in width. It is typically unbranched, with a flat or slightly concave top. Most of the plant remains below ground, with only a few centimeters visible above the surface. During dry periods, it contracts into the soil for protection. The stems are thickly covered in dense, pale-colored spines, giving the plant a white or yellowish appearance. The spines are short, with the longest reaching about 7 mm. Each areole can bear up to 90 spines, which lie flat against the stem and form dense clusters. The plant almost always grows solitary, with small, smooth, glossy stems. When dried out or losing turgor, sunken rings may appear on the surface. Young plants look very similar to mature ones, making early identification challenging. The flowers are delicate, pale pink to silvery white, protruding above the spines at the stem apex. They measure 1 to 1.7 cm long and wide, with 13 to 21 translucent inner tepals marked by pink, pinkish-tan, or greenish-yellow lines, and 8 to 13 outer tepals with scalloped edges. The flowers contain 20 to 40 stamens and white stigma lobes. …

The species' native range extends from Texas in the United States to northeastern Mexico, specifically within the states of Coahuila and Chihuahua in desert or dry scrubland environments at elevations between 700 and 1,500 meters above sea level. The species is a soil specialist, often forming dense clusters on specific calcareous substrates. It is commonly found on elevated limestone hills, mountain summits, and rocky ledges within xerophytic scrublands. Additionally, the species can occur on plains, where it grows on soils composed of gravel mixed with organic-rich earth resulting from leaf decomposition. These conditions provide localized nutrients and enable the species to thrive in extremely dry environments. Plants are found growing along with Coryphantha difficilis, Ariocarpus fissuratus, Echinocereus pectinatus, Sclerocactus scheeri, Mammillaria heyderi. Threats to the species include poaching and habitat degradation. It is in cultivation at the Desert Botanical Garden in Phoenix, Arizona.