The crown of thorns (Euphorbia milii) is a flowering succulent belonging to the Euphorbiaceae family. It is native to Madagascar, but it can be found in tropical and subtropical regions around the world. It is most recognizable by its long, sharp thorns and burgundy-colored flowers. The plant features deep green leaves and can grow up to 2 feet in height. The crown of thorns is an attractive plant that is often used in landscaping and flower arrangements.