For the family commonly called "euphorbias", see Euphorbiaceae

Euphorbia (spurge) is a very large and diverse genus of flowering plants in the spurge family (Euphorbiaceae). Sometimes in ordinary English, euphorbia is used to refer to the entire Euphorbiaceae family (as the type genus), not just to members of the genus. Some euphorbias are well known and widely commercially available, such as Poinsettias at Christmas. Some are commonly cultivated as ornamentals, or collected and highly valued for the aesthetic appearance of their unique floral structures, such as the Crown of Thorns plant. Euphorbias from the deserts of Southern Africa and Madagascar have evolved physical characteristics and forms similar to cacti of North and South America, so they (along with various other kinds of plants) are often incorrectly referred to as cacti, although they are far from being related as plants, see below. Some are used as ornamentals in landscaping, because of beautiful or striking overall forms, and drought and heat tolerance. Botanists may be fascinated by the diversity or bizarreness of some of the floral structures, and by the range of growth forms and adaptations to such a wide range of habitats.