Echinopsis is quite an extended genus native to South America also known as 'hedgehog cactus, sea-urchin cactus or Easter lily cactus'. The small species Echinopsis chamaecereus is called 'the peanut cactus'. Some taxonomists have recently enlarged the genus Echinopsis by including into it, such genera as Trichocereus and Lobivia. The name derives from echinos - hedgehog or sea urchin, and opsis appearance, a reference to these cacti, dense coverings of spines. Its a poorly understood genus of South American cacti, one of the largest genera of cacti as defined by the International Cactaceae Systematics Group. Echinopsis comprises 128 species and one naturally occurring hybrid.