Plants from the Euphorbiaceae family are often mistaken for cactus. It is not generally known, but cactus are indigenous to the American continents. There are no native cactus plants on any other continent including Africa, one the homes of the Euphorbiaceae. These plants are commonly called Euphorbias. Members of this plant family are found throughout the warmer climate areas of the world, with most of the varieties in the Indo-Malayan region and tropical America. See Wikipedia: Euphorbiaceae.