Bougainvillea  is a genus of thorny ornamental vines, bushes, and trees with flower-like spring leaves near its flowers. Different authors accept between four and 18 species in the genus. They are native plants of South America from Brazil west to Perú and south to southern Argentina (Chubut Province). Bougainvillea are also known as buganvilla (Spain), bugambilia (Mexico), Napoleón (Honduras), veranera (Colombia, Nicaragua, El Salvador, Costa Rica and Panama), trinitaria (Colombia, Cuba, Panama, Puerto Rico, Dominican Republic & Venezuela), Santa Rita (Argentina, Bolivia, Brazil, Paraguay and Uruguay) or papelillo (northern Peru).

The vine species grow anywhere from 1 to 12 m (3 to 40 ft.) tall, scrambling over other plants with their spiky thorns. The thorns are tipped with a black, waxy substance. They are evergreen where rainfall occurs all year, or deciduous if there is a dry season. The leaves are alternate, simple ovate-acuminate, 4–13 cm long and 2–6 cm broad. The actual flower of the plant is small and generally white, but each cluster of three flowers is surrounded by three or six bracts with the bright colours associated with the plant, including pink, magenta, purple, red, orange, white, or yellow. Bougainvillea glabra is sometimes referred to as "paper flower" because the bracts are thin and papery. The fruit is a narrow five-lobed achene.

Bougainvillea are relatively pest-free plants, but may suffer from worms, snails and aphids. The larvae of some Lepidoptera species also use them as food plants, for example the giant leopard moth (Hypercompe scribonia).