Obtained from the candelilla plants; Euphorbia antisyphilitica Zucc., Euphorbiaceae and E. cerifera Alcocer (which is only doubtfully distinct from E. antisyphilitica) are now the principal sources of candelilla wax. Pedilanthus pavonis Boiss. and P. aphyllus Boiss. are secondary sources, yielding a wax of lower melting range and lower saponification number. Most of the wax is produced in Mexico by immersing the plants in boiling water containing sulfuric acid and skimming off the wax which rises to the surface as described by Dickinson, Am. J. Pharm. 91, 808 (1919); Hodge, Sineath, Econ. Bot. 10, 134 (1956). The main constituent is the hydrocarbon hentriacontane. Brief review: C. S. Letcher in Kirk-Othmer Encyclopedia of Chemical Technology vol. 24 (Wiley-Interscience, New York, 3rd ed., 1984) pp 468-469.