Origin:
Native to South America, but introduced to the United States and sold as aquatic plants. It was planted in ponds and aquariums and has now spread widely across North America.
Biology:
An aquatic perennial, rooted on the bottom but with the majority of the vegetation floating at or above the water surface. It is a highly reproductive plant, propagating from seeds as well as from the stems that break off and are easily transported and root at the nodes. This plant is capable of covering vast surfaces of water in ponds or slow-moving streams, substantially reducing the flow of the water as well as the carrying capacity and usefulness of the pond to wildlife.
Identification:
Mature plants have long stems arising from the bottom and with very few branches. At the surface they grow the vegetative parts, as long stems heavily lined with whorls of leaves. There are 4 to 6 leaves in a whorl at each point along the stem, and leaves are very narrow and up to 2 inches long. The leaves are divided along their margins into narrow teeth, from 10 to 18 teeth along each side of the mid-vein, giving the leaves a distinct feather-like appearance. The flowers are primarily female flowers that grow as small, white tufts at the bases of the leaves.
Characteristicts Important to Control:
Physical removal is almost fruitless, as the stems easily snap off when disturbed, and if left behind as pieces will grow new plants.
