Genus of about 2000 species of annuals, biennials, evergreen, semi-evergreen, or herbaceous perennials, deciduous or evergreen subshrubs, shrubs and trees and succulents, from a temperate, or tropical and subtropical regions. Euphorbias are often mistaken for cacti because of their columnar shape and spines. They are succulents like cacti but also, usually, have leaves. There are two common types of Euphorbia, woody stemmed plants like poinsettias and crown of thorns, and the smooth cacti - like Euphorbias.