Amaranthaceae

Alternanthera philoxeroides

Common Names: Alligator weed

Plant Form: Creeping aquatic weed. Size: Mats of up to 15 m. Stem: Hollow, interwoven, creeping, up to 60 cm tall and 10 m long. Leaves: Spear shaped without stalk, in opposite pairs. Flowers: Small, white, papery 8-10 mm diameter on short stalks. Fruit and Seeds: Reproduces vegetatively. Habitat: Riparian areas and floodplains. Distinguishing Features: Distinguished from other Alternanthera species by the flowers being on stalks. Impacts: Outcompetes pasture and native species, possibly toxic to cattle. Large infestations can block water access.