in botany: A genus of the trigynia order, belonging to the triandra clas of plants. The calyx is a triphyllous perianthium, with short subulate leaves standing at a distance from one another. The corolla has from eight to ten petals of an oblong linear shape, twice as long as the calyx. The stamens are three filulated filaments the length of the calyx; the antherae roundish, didymous, and two-lobed at the base.