Ritual Black Drink consumption at Cahokia.

Chemical analyses of organic residues in fragments of pottery from the large site of Cahokia and surrounding smaller sites in Illinois reveal theobromine, caffeine, and ursolic acid, biomarkers for species of Ilex (holly) used to prepare the ritually important Black Drink. As recorded during the historic period, men consumed Black Drink in portions of the American Southeast for ritual purification. This first demonstrated discovery of biomarkers for Ilex occurs in beaker vessels dating between A.