Ilex cassine is a holly native to the southeastern coast of North America that grows from Virginia to the Colorado River in Texas, with subspecies growing southward on the Gulf Coast as far as Veracruz, Mexico, and in Cuba, Puerto Rico, and the Bahamas in the Caribbean.

[10] It is cultivated in warmer climates as an ornamental plant for the attractive bright red berries set against the glossy green leaves.

[4] Ilex cassine leaves, like those of its sister species I. vomitoria, contain measurable amounts of the stimulants caffeine and theobromine.

An analysis of the levels of methylxanthines in the leaves used in various stimulant drinks found that I. cassine leaves have about 20% (by dry weight) of the amount of caffeine found in I. vomitoria, 8% of that in Coffea arabica, and about 3% of the caffeine in Camellia sinensis Kunze.

[4] The Native peoples of Florida used the hollowed-out shells of Lightning Whelks (Busycon contrarium), a kind of sea snail found on the east and west coasts of Florida, as drinking vessels in their black drink ceremonies.