The Collaborative International Dictionary
Yaupon \Yau"pon\, n. (Bot.) A shrub ( Ilex Cassine) of the Holly family, native from Virginia to Florida. The smooth elliptical leaves are used as a substitute for tea, and were formerly used in preparing the black drink of the Indians of North Carolina. Called also South-Sea tea. [Written also yapon, youpon, and yupon.]
Wiktionary
n. A tea-like drink made by Native Americans, and then by others, having exhilarant and diuretic properties. It is thought to have been brewed with (taxlink Ilex vomitoria species noshow=1) (yaupon) or (taxlink Ilex cassine species noshow=1) leaves, although this is not certain.
Wikipedia
Black drink is a name for several kinds of ritual beverages brewed by Native Americans in the Southeastern United States. Traditional ceremonial people of the Yuchi, Caddo, Chickasaw, Cherokee, Choctaw, Muscogee and some other Indigenous peoples of the Southeastern Woodlands use the black drink in purification ceremonies. It was occasionally known as white drink because of the association of the color white with peace leaders in some Native cultures in the Southeast.
Black drink is consumed to purify an individual by removing spiritual and physical contamination and, as such, is never taken casually. The preparation and protocols vary between tribes and ceremonial grounds. The full formula is not published or given to outsiders, but a prominent ingredient is the roasted leaves and stems of Ilex vomitoria (commonly known as yaupon holly), a plant native to the Atlantic and Gulf Coasts. Black drink usually contains emetic herbs, which has been recorded as inducing vomiting.