Epithelantha micromeris (Button Cactus)

Scientific Name

Epithelantha micromeris (Engelm.) F.A.C.Weber ex Britton & Rose

Common Names

Button Cactus, Living Rocks, Pingpong Ball Cactus

Synonyms

Mammillaria micromeris (basionym), Epithelantha micromeris subsp. micromeris, Epithelantha micromeris var. micromeris, Epithelantha petri

Scientific Classification

Family: Cactaceae
Subfamily: Cactoideae
Tribe: Cacteae
Subtribe: Cactinae
Genus: Epithelantha

Description

Epithelantha micromeris is a cactus characterized by its white-grey spines growing on a globular shaped stem. The density of its white spines give it the illusion of being completely grey, making it very difficult to see the green color beneath. It grows to be up to 2 inches (5 cm) tall, and up to 1.6 inches (4 cm) in diameter. It produces small, pink-white flowers, often considered to be some of the smallest of the cacti. These flowers give way to a bright red, cylindrical fruit which contains several black seeds and also is edible.

Photo via picssr.com

How to Grow and Care

To encourage better flowering, allow the plants to enjoy a cooling period in the winter and suspend watering. Unlike many other cacti, which use their ribs as storage devices, the Mammillaria feature raised tubercles, from which spines emerge. When you water, the tubercles will expand to allow for increased water storage. The flowers emerge from the axils of these tubercles on the previous year’s growth, which accounts for their interesting halo effect. It’s imperative that the cactus is not exposed to prolonged dampness and sitting water. Never let your cactus sit in a dish of water. Lastly, make sure to fertilizer during the growing season for the best results.

Repot as needed, preferably during the warm season. To repot a cacti, make sure the soil is dry before repotting, then gently remove the pot. Knock away the old soil from the roots, making sure to remove any rotted or dead roots in the process… – See more at: How to Grow and Care for Mammillaria

Origin

The species occurs in the United States in Arizona, New Mexico and Texas, and in Mexico in the states of Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí and Zacatecas.