Astrophytum ASTERIAS - Star peyote, Sand dollar cactus, Star cactus, Astrophytum asterias.
Astrophytum is a genus of succulent plants in the cactus family (Cactaceae), comprising 6 species and numerous varieties and forms growing on rocky and limestone soils in the foothills and mountains of northeastern Mexico and Texas.
Members of the genus are known for solitary, spherical, or cylindrical ribbed bodies and almost complete absence of spines, although some species do have a few curved needles. The surface can be smooth or covered with white scales forming unusual light, felted, marble patterns on the surface of the stem that are capable of absorbing moisture. There are no leaves; the plant body is green, often with a glaucous bloom, adorned with areoles with spines.
These cacti grow very slowly, but bloom early with large, funnel-shaped, yellow flowers, sometimes with a red center, located at the apex of the stem. The flowers usually fade after two to three days. With proper care, flowering lasts for an extended period, from spring to late autumn. Fleshy, pubescent fruits with thin skin contain black or brown seeds.
Astrophytum asterias belongs to the type of "spineless" cacti (lacking spines), having a spherical, slightly flattened stem reaching 8-10 cm (3.1-3.9 in) in diameter and 6-8 cm (2.4-3.1 in) in height. On its surface, 6-8 weakly defined ribs are visible. Axillary buds (so-called "areoles") are located in the middle of the ribs. Nearby are white flecks that give the surface of the cactus a special ornamental appeal. In general, the cactus resembles a sea urchin test. The diameter of its silky yellow flowers is 6-7 cm (2.4-2.8 in), with a length of 3 cm (1.2 in). Their center can have a reddish tint.
Flowering begins relatively early. Flowers usually open in early summer during daytime hours. Cacti growing in a sunny location acquire a characteristic bronze tint over time. This species easily forms hybrids with Astrophytum myriostigma.