Epithelantha
The succulents in this group are slow growing, dwarf cacti. They are natives of the western U.S. and Mexico and are found growing in shallow soil on rocky hillsides. E. micromeris (Button Cactus) is a tiny, globular species that will reach a height of only 4 inches and make clusters up to 51/2 inches wide. Its pale green body is covered with small, white spines. The Button Cactus will flower when it is only 3/4-inch high. From early spring to mid-summer, tiny, white to pale pink flowers grow up from the densely spined crown. They are followed by interesting, small, hot pink fruits that stand up from the crown like tiny fingers. E. micromeris var. unguispina is different from the other species in that it has a short (under 1/4-inch), black-tipped, central spine and larger, darker pink blossoms.
Pot Cultivation
These plants need very coarse potting soil in a shallow pot that drains well, because they are very prone to rot. They like sun, but can't tolerate full sun all day.
Propagation
Seeds can be sown in the spring or summer in well-drained pots of sandy soil that are half-filled with crocks. Make sure the surface is evenly smooth and sow the seeds thinly on top. Cover them with a bit of fine soil. Moisten and lay a piece of glass across the top. The pots should be set in a warm greenhouse or sunny window until they start to sprout after which the glass should be removed so they can receive full light and air. It isn't good to keep the glass over the seedlings, so if some of them are up before others, they may be pricked out and placed in another pot. The transplanted seedlings should not be disturbed until they are well rooted after which they can be planted separately in small pots. Offsets may be detached and laid aside for a few hours to allow a protective skin to form over the cut. They may then be planted in coarse sandy soil to root.
VARIETIES
E. micromeris & var. unguispina.