Euphorbia antisyphilitica

Euphorbia antisyphilitica, known as candelilla and sometimes wax plant, is a shrubby flowering plant of the spurge family, Euphorbiaceae. It grows wild in the Trans-Pecos region of Texas and in southern New Mexico in the United States, and across the Mexican states of Chihuahua, Coahuila, Hidalgo and Queretaro. Its stems are densely clustered, upright and essentially leafless, and they are coated in wax that limits water loss through transpiration, an adaptation to arid country. The plant is best known for that wax. Commercial harvest of candelilla wax began early in the twentieth century and grew sharply during the two World Wars, then largely collapsed after 1945 as wild populations thinned and cheaper petroleum waxes became available. Wax is still produced in northern Mexico, notably in Coahuila, for cosmetic and food uses. The species name records an old claim that it treated syphilis, but the source notes no documentation that indigenous communities used it so. Candelilla is also grown as a low-water landscape plant in the arid American southwest, and it is listed in Appendix II of CITES, so international trade in it requires permits.