Wikipedia
Echinopsis is a large genus of cacti native to South America, sometimes known as hedgehog cactus, sea-urchin cactus or Easter lily cactus. One small species, E. chamaecereus, is known as the peanut cactus. The 128 species range from large and treelike types to small globose cacti. The name derives from echinos hedgehog or sea urchin, and opsis appearance, a reference to these plants' dense coverings of spines.
Echinopsis is distinguished from Echinocactus by the length of the flower tube, from Cereus by the form and size of their stems, and from both in the position on the stem occupied by the flowers. They are remarkable for the great size, length of tube, and beauty of their flowers, which, borne upon generally small and dumpy stems, appear much larger and more attractive than would be expected.
Echinopsis is an extinct genus of sea urchins in the class Echinoidea.
These slow-moving low-level epifaunal grazers lived from the Cretaceous to the Paleogene periods (125.45 - 5.332 Ma). Fossils of this genus have been found in the sediments of Madagascar, Pakistan, Senegal, Sudan, United States and Switzerland.