Alisma subcordatum (American water plantain) is a perennial aquatic plant in the Water-plantain family (Alismataceae). This plant grows to about 3 feet (1 meter) in height with lance to oval shaped leaves rising from bulbous corms with fibrous roots. Any leaves that form underwater are weak and quick to rot; they rarely remain on adult plants. A branched inflorescence with white to pink 3 petaled flowers blooms from June to September. The seeds are eaten by waterfowl and upland birds. The species name subcordatum means "almost heart-shaped".