in botany, a genus of annual or perennial climbing herbs belonging to the natural order Cucurbitaceae, natives of the tropics, especially Africa, and known in cultivation chiefly as hothouse plants. They are grown for their ornamental fleshy fruits, which are oblong to cylindrical in shape, orange to red in colour, prickly or warted externally, and burst when ripe, generally with elastic force, into irregular valves. M. Balsamina, known as balsam apple, is a very pretty annual, well adapted for trellises, &c., in warm outside situations.