Scientific name

Ottelia Pers.

Common names

duck lettuce, santawaa, water plantain



Could be confused with

Aponogeton, Damasonium, Echinodorus

Native distribution

Africa, Asia, Australia, and South America

Species commonly cultivated

Ottelia alismoides (L.) Pers. (Asia to Australia)

O. mesenterium (Hallier fil.) den Hartog (Indonesia)

O. ovalifolia (R. Br.) Rich. (Australia)

O. ulvifolia (Planch.) Walp. (Africa, Madagascar)

U.S. Federal Noxious Weed: Ottelia alismoides

Identification: Ottelia alismoides is distinguishable from most Ottelia species by its large, light green, ovate to rounded leaves with undulate margins in mature plants, lack of floating leaves, and white flowers with yellow center.

See Ottelia alismoides disseminule fact sheet.

Adventive distribution

Ottelia alismoides is introduced in several states in the southern United States. Ottelia ovalifolia is introduced in New Zealand; its presence in New Caledonia is not confirmed.

Weed status

Ottelia alismoides is an aquatic weed on the U.S. federal noxious weed list.


large, submersed or floating, attached rosette plant

Brief description

Annual or perennial. Monoecious or dioecious. Stem typically compact, roots unbranched. Leaves in a basal rosette, sheathed at base, juvenile leaves usually sessile, mature leaves numerous, often petiolate, submersed and/or floating; mature leaf blade linear, reniform to orbicular, veins parallel or palmate; base rounded to cordate; margin entire or undulate. Spathe of 2 united bracts, often winged or ribbed. Flowers unisexual or bisexual; female and bisexual flowers sessile, solitary; male flowers numerous, pedicellate, emerging from spathe; sepals 3, green; petals 3, conspicuous, yellow, purple, white or pink, or reduced in cleistogamous flowers. Dispersal by numerous seeds.

Natural habitat

usually in slower waters of rivers, lakes, and ponds

Additional comments

Ottelia contains 21 species; 13 species in Africa, seven in Asia and Australia, and a single species in South America. A great deal of taxonomic confusion is associated with this genus due to the high degree of polymorphism in several species, especially O. alismoides. Although robust plants of Ottelia occur in the wild, only a few species (or varieties) are suitable for aquarium or pond cultivation, and they remain difficult species to maintain in permanent culture.