ALLAMANDA, in botany; a genus of the monogynia order, belonging to the pentandria class of plants. The characters are: The calyx is a five-leaf'd perianthium: The corolla consists of one funnel-shaped petal; the tube cylindric; the border semiquinquefid and ventricose; the divisions expanding and obtuse: The stamina have scarce any filaments; the anthers are five, arrow-shap'd, converging, in the throat of the tube: The pistillum has an oval germin, girt at the base with an annular margin; the stylus is filiform, the length of the tube; the stigma is headed, and contracted in the middle: The pericarpium is an orbicular, compress'd, bristly capsule, containing one cell with two valves: The seeds are imbricated, orbicular, flat, with a membranaceous wing on the margin, and are very numerous. There is but one species, the cathartica, a native of Surinam.