A taro family plant which grows in water. It grows to 30-45 cm high and 60-75 cm across. It has large thick rhizomes. The leaves are narrowly oblong. They can be under the water, floating on the water, or above the water. The leaves can be 25 cm long. The leaves often have a purple tint underneath. The flowers are small and bright yellow. These are near the top of cylinder shaped white flower stalks. The flower stalks are 18 cm long.
Petioles 1–2 dm; blades elliptic, 6–20 cm, a third as wide, acute, narrowed below to an obtuse or acute base, the veins parallel from base to apex, with numerous transverse connecting veinlets; scape 2–4 dm, flattened above; spadix 2–5 cm; 2n=26. Swamps and shallow water, especially on the coastal plain; Mass. to Fla., w. to c. N.Y., sw. Pa., e. Ky., w. Tenn., and La.