AMASONIA, in botany: A genus of the angiospermia order, belonging to the didynamia class of plants; the characters of which are: The calyx is a tripartite monophyllous perianthium, bell-shaped and persistent: The corolla is monopetalous and tubular; the border quinquefid, expanding, and small: The stamens consist of four filaments longer than the corolla; the anther oval and incumbent: The pistillum has an ovate germin; the style the length of the lamina; the stigma two, acute: There is no pericarpium: The seed is an ovate-unilocular nut, the length of the calyx.