What is "pediocactus"

Pediocactus ( Greek: πεδίον (pedion) means "plain", "flat", "field") is a genus of cacti. The genus comprises between 6 and 11 species, depending upon the authority. Species of this genus are referred to as hedgehog cacti, though that name is also applied to plants from the genera Echinocereus and Echinopsis. Species may also be referred to as pincushion cacti, a common name which is also applied to other genera.