Duration: Perennial
Nativity: Native
Lifeform: Forb/Herb
General: Perennial, matted herb with stems floating or creeping, 10-30 cm long, decumbent, rooting at nodes, subglabrous.
Leaves: Opposite, less than 5 cm, narrowly elliptic to round, entire, subglabrous to densely and minutely strigose.
Flowers: Axillary, sepals 4, 1.8-5 mm; petals 4, 1-3 mm, yellow, stamens 4 anthers 0.4-0.9 mm.
Fruits: Erect, pedicel 0-3 mm, fruit 4-10 mm, oblong to narrowly obconic, sometimes hairy.
Ecology: Grows along waters edge, or along sandy streambanks, ponds, and ditches from 2,500-5,000 ft (762-1524 m); flowers July-September.
Notes: Always along streams, this species is invasive in Puerto Rico, but native to lower-48.
Ethnobotany: Unknown for this species, other species in genera have medicinal use.
Etymology: Ludwigia is named for Christian Gottlieb Ludwig (1709-1773) a German botanist, while repens means having creeping and rooting stems.
Synonyms: Isnardia intermedia, Isnardia repens, Ludwigia natans, Linnaeus natans var. stipitata, Linnaeus repens var. rotundata, Linnaeus repens var. stipitata
Editor: SBuckley, 2010