Bougainvillea, a neotropical genus of Nycta- ginaceæ, frequently trained over trellises or under the roofs of greenhouses, on account of the beauty of its peculiar inflorescence, the small flowers, which grow in threes, being almost concealed by as many membranous bracts of splendid rosy or purple colour.—The same name is given to a genus of hydroid zoophytes.