water purslane

noun

1. a creeping, Eurasian annual plant, Lythrum portula, of marshes and wetlands, having small flowers and rounded leaves.
2. an aquatic herb, Peplis diandra, of the central U.S. and Mexico, having small flowers.
3. a widely distributed herb, Ludwigia palustris, of marshes and wetlands, having small flowers.

water purslane

noun

1. an onagraceous marsh plant, Ludwigia palustris, of temperate and warm regions, having reddish stems and small greenish flowers
2. any of several lythraceous plants of wet places that resemble purslane, such as Peplis portula of Europe, which has small pinkish flowers, and Didiplis diandris of North America, which has small greenish flowers