The genus Acanthocalycium is a small genus consisting of 5 to 7 species depending on who you talk to. Taxonomists have lumped Acanthocalycium in to Echinopsis and removed and lumped in again. Where it should be located is still debated. All species are from Argentina and can be found just above sea level to around 1500m. These plants are mostly globule with some elongating. Flowers come in early summer and can white, pink or red. All species are relatively easy in cultivation and are a great plant for beginners.