Euphorbia is a very large and diverse genus of flowering plants, commonly called spurge, in the spurge family. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae, not just to members of the genus.
Euphorbia plants (Euphorbia spp.) also go by the easier to say, but less elegant, name of Spurge. They are a family of plants that may be grown as houseplants or occasionally outdoors. There are many varieties of Euphorbia plants, with fascinating forms that range from shrubs, herbs, or cactus-like specimens. Euphorbias occur naturally in many parts of the world, but most notably Africa, Asia, Europe and North and South America. The variation of form and size provide a spectacle of plant life. Some are as large as trees and others range as small ground covers. There are over 2,000 species, many of which you will find familiar from interior commercial plantings. Crown of thorns is recognizable by its spiky stems, and donkey spurge is aptly named with thick rope-like stems sprawling away from the plant. Invasive in the US.