Indigenous to Africa the genus Aloe includes herbs, shrubs and trees bearing spikes of white, yellow or red flowers. Many species have been introduced into West Indies and Europe. Aloe comprises about 450 species in Africa and Arabia of which about 315 occur in mainland Africa, about 100 are endemic to Indian Ocean islands and 50 occur in Arabia. The taxonomy is complicated by the occurrence of interspecific hybrids both in the wild and in cultivation. The drug aloes is mainly obtained from

• Aloe barbadensis Miller (Aloe vera Linne) – known in commerce as Curacao aloes and collected from the West Indian islands of Curacao, Aruba and Bonaire;
• Aloe ferox Miller and hybrids with A. africana Miller and A. spicata Baker – known as Cape aloes cultivated in South Africa and Kenya;
• A. perryi Baker – found in east Africa and Arabia and yields Sacotrine and Zanzibar varieties.

Today Aloe vera is distributed throughout the tropics and subtropics and is widely grown as a cash crop in dry regions in the Americas, Asia and Australia.