Characters.—Calyx superior, of 3 sepals, short. Corolla tubular, irregular, with the segments in 2 whorls; the outer 3-parted, nearly equal, the inner very irregular; one of the lateral segments usually coloured, and formed differently from the rest; sometimes by abortion fewer than 3. Stamens 3, petaloid, distinct, of which one of the lateral and the intermediate one are either inactive or abortive, and the other lateral one fertile. Filament petaloid, either entire or 2-lobed, one of the lobes bearing the anther on its edge. Anther 1-celled, opening longitudinally. Pollen round (papillose in Canna coccinea, smooth in Calathea zebrina). Ovary 1-3-celled; ovules solitary and erect, or numerous and attached to the axis of each shell; style petaloid or swollen; stigma either the mere denuded apex of the style, or hollow, hooded, and incurved. Fruit capsular, as in Scitamineae. Seeds round, without aril; albumen hard, somewhat floury; embryo straight, naked, its radicle lying against the hilum. Herbaceous tropical plants, destitute of aroma. Rhizome often tuberous, and abounding in starch. Stem often branching. (Lindley.)
Properties.—The rhizomes frequently abound in starch.