duck lettuce, santawaa, water plantain
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.
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.
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.
usually in slower waters of rivers, lakes, and ponds
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.