Button Cactus

Scientific Name: Epithelantha micromeris (Engelmann) Weber
Synonym: Cactus micromeris, Epithelantha densispina, Epithelantha micromeris var. densispina , Epithelantha micromeris var. rufispina , Epithelantha rufispina, Mammillaria micromeris
Family: Cactaceae

Recommended Temperature Zone:
USDA: 8b-11

Frost Tolerance: Depending on the variety, will take 10° F (-12° C)

Sun Exposure: Light shade to full sun

Origin: USA (Arizona: Santa Cruz and Cochise County, New Mexico, western Texas), Mexico (northern Chihuahua). In desert and grasslands from 3000 to 4500ft (1000 to 1500m) of elevation

Growth Habits: Often clumping, globose stems up to 1 inch in diameter (2.5 cm), occasionally more; small tubercles, 1 mm long; small areoles, slightly woolly when young; 20 or more white spines, 2 mm long, longer on the top.

Watering Needs: Moderate water. The Button Cactus needs a soil mix draining particularly well, since it needs a deeper pot due to its tap root.

Propagation: Seeds, offsets

The Epithelantha contains hallucinogenic alkaloids. The name comes from the Greek for "flower at the top of the nipple", a reference to the fact that the flowers doesn't originate between the nipple as in the genus Mammillaria. The variety greggii originates from Coahuila in Mexico. The second pictures shows a form with a well developed central spine.

Blooming Habits:
The Button Cactus has 0.2 inch long (5 mm), 0.16 inch wide (4 mm) pale pink flowers that appear in May-June at the apex of the plant. They only partly opens, as they barely stick out above the wool an spines at the top of the plant. They are followed by thin red fruit, 0.3 to 0.5 inch long (8-12 mm).