Kroenleinia grusonii (Golden Barrel Cactus)

Native to Mexico, this perennial succulent cactus develops a rounded green stem that gradually lengthens into a barrel shape as it matures. Prominent ribs carry dense golden spines, and a woolly area covers the crown. Mature plants produce yellow flowers in a ring near the top, partly hidden among the pale hairs. Small fruits contain numerous tiny black seeds. The species is propagated for ornamental use in containers and dry gardens. Although widely cultivated, it is endangered in the wild. Photographed in Colombia.