Nymphoides cordata aka Little Floatingheart

Nymphoides cordata, or little floatingheart, lives in fresh water. It is a perennial, so it lives for many years. It belongs to the buckbean family, Menyanthaceae. Its native range spans southeastern Canada and the eastern United States. It reaches as far south as Florida. It grows in lakes, streams, and rivers where water flows slowly. In North Carolina, it grows mainly in the Sandhills. It grows in temperate regions and suits freshwater gardens.

The plant spreads flat across the water. It has underground stems called rhizomes. Thick roots float in clusters. Its green stems are long, thin, round, and smooth. The simple leaves grow one after another, on alternate sides. Each leaf has a heart or egg shape. Its smooth edges have no teeth. The top is green and may have reddish-purple patches. The smooth underside has a red or purple cast. Leaves are about 0.10–0.23 feet [0.03–0.07 metres] long.

Upright green stems hold blooms above the leaves. Each stem bears one small flower shaped like a cup. Blooms are white or cream, with yellow at the centre. Each has five petals and spans about 0.04 feet [0.013 metres]. The source gives April through August as the bloom season. It lists summer as the main time for flower display. The fruit forms a capsule, which opens to shed seeds. It sheds seeds from May through September. The flowers draw pollinators to the water garden.

Grow little floatingheart under fresh water, in full or part sun. It suits ponds, streams, and pots sunk in large tubs. It accepts clay, loam, and sand where water stays available. It grows at a moderate rate and needs little care. The listed hardiness range is USDA zones 5 through 10. The source lists root and stem cuttings as ways to grow new plants. Small groups suit native gardens and water gardens. Growth below water gives small water animals places to live. Other water wildlife then feed on these animals.

The source reports no major problems with pests or disease. Parts of the United States and Canada class it as imperiled or endangered. These local concerns do not show its global conservation status. Native Americans used this plant as medicine. The evidence gives no ways to prepare it or guidance on safe use. It does not show whether humans can eat it. Nor does it show whether the plant is toxic.