Echinopsis is a genus of cacti native to South America, sometimes known as hedgehog cactus, sea-urchin cactus or Easter lily cactus. As of October 2023, there are about 20 accepted species, ranging 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 lageniformis, synonyms including Echinopsis scopulicola and Trichocereus bridgesii, is a cactus native to Bolivia. It is known as the Bolivian torch cactus. Among the indigenous populations of Bolivia, it is sometimes called achuma or wachuma, although these names are also applied to related species such as Trichocereus macrogonus which are also used for their psychedelic effects.