Shrubs or trees; pubescence of simple hairs. Leaves subentire, mostly ovate, petiolate. Flowers very large, usually fragrant, solitary at leaf nodes near the branch ends, perfect, actinomorphic, 5-merous; calyx tubular, 5-lobed or spathaceous; corolla white, pink, red, greenish, or yellowish, trumpet shaped, mostly with 5 pointed teeth; stamens inserted near the middle of the corolla tube, sometimes geniculate, equal, pubescent or not, anthers linear, basifixed, longitudinally dehiscent; ovary 2-locular. Fruit an unarmed, elongate or rotund woody indehiscent capsule; embryo straight, immersed in the endosperm.
About five species, all in South America, two widely cultivated; one species commonly escaping in Taiwan.