This is Ludwigia alternifolia, also known as Seedbox, and Bushy Waterprimrose. This plant likes a wet swampy soil. Growing 2 to 3 feet tall this plant prefers to live in full sun or partial shade, blooming from the middle of Summer until early Fall. The box shaped seed pods give it its common name seed box. This seed pod draws as much attention as the flower itself does. These seed pods are essential in the spread of this plant. They can float on water or be blown around by the wind, dropping seeds out of the box the whole way. Although this plant does draw interest from small butterflies and the Pearly Wood Nymph, it is mostly utilized by all sorts of bees. USDA Hardiness Zones 4 to 8