Water purslane creeps along the edges of ponds and streams where conditions defeat most ornamentals: waterlogged mud, shallow water, shifting margins. Its succulent stems flush red in direct sunlight, and the plant spreads outward along the ground or reaches toward the water surface depending on conditions, rooting at every node to form stabilizing mats. Zones 3 through 7, it handles cold well and returns reliably where winters allow, making it a practical choice for rain gardens and bioswales where some filtering of runoff is welcome alongside the aesthetic.

Flowers are inconspicuous green affairs appearing midsummer through fall, but this plant earns its place through function rather than floral display. It is widely traded in the aquarium hobby for its tolerance of submersion and its tidy, manageable growth. In the garden, it works well at the water's edge where erosion is a concern and conventional plants struggle to establish.