Origin:
Native to South America – one of over 30 species of Ludwigia in the United States.
Biology:
A perennial aquatic weed that infests irrigation and drainage ditches, ponds, and slowly running streams or sloughs. Its growth can be extensive enough to interfere with navigation by small boats. Seeds germinate throughout the spring, growth is vigorous throughout the summer, and the foliage dies back in the winter. Mature plant generally roots in bottom mud, but also has very long, floating stems that develop roots at the nodes.
Identification:
Floating stems may reach 6 feet in length, and upright stems can extend as high as 16 inches above the water level. If these stems reach the muddy banks they may root in the soil as well. Leaves are oblong, oval, or spatula-shaped, narrowing toward the base. Leaves appear alternately on the stems, on stalks over 1 inch long. Veins on the leaf are distinctly lighter in color than the leaf surface. Flowers are deep yellow, 5 petals, and over 1 inch across. They appear as single flowers on stalks arising from the leaf axils.
Characteristicts Important to Control:
Aquatic, but rooting in the soil at the edges of ponds or slow waterways. A perennial that dies back in the winter.
