The banana plant is a gigantic herb that springs from an underground stem, or rhizome, to form a false trunk 3–6 metres (10–20 feet) high. This trunk is composed of the basal portions of leaf sheaths and is crowned with a rosette of 10 to 20 oblong to elliptic leaves that sometimes attain a length of 3–3.5 metres (10–11.5 feet) and a breadth of 65 cm (26 inches)