Plantains meaning : A plant of the genus Plantago, with a rosette of sessile leaves about 10 cm long with a narrow part instead of a petiole, and with a spike inflorescence with the flower spacing varying widely among the species. See also psyllium. A plant in the genus Musa, the genus that includes banana, but with lower sugar content than banana. The fruit of the plant, usually cooked before eating and used like potatoes.