Many-branched aquatic plant with upright, narrow, bright green leaves that are crowded on the upper stems. It grows entirely underwater except for tiny white flowers that grow on delicate stalks which elongate so that they bloom on the water's surface.
Stems erect, branched, rooted in substrate; leaves narrow, tips pointed, not stemmed, mostly in 3s in whorls, submerged; flowers enclosed by bracts; male and female flowers on separate plants, petals white and 3, styles 3, not 2-parted.
Habitat
Found in calcareous (chalky or containing limestone) often slow-moving waters of lakes, rivers, ponds, streams as well as in ditches.
Flower Characteristics
Male and female flowers grow on separate plants. Flowers have 3 petals, 3 oval leaf-like sepals and thread-like stalks which elongate enabling them to bloom on the water's surface. Petals are 1/8 to 1/4 inch long and narrow greatly at the base (clawed).
Leaf and Stem Characteristics
Stems are anchored in the mud at the water bottom by fibrous roots. The smaller basal leaves have an opposite attachment but most of the leaves grow in whorls of 3 along the mid to upper stem. Leaves are 1/4 to 3/4 inch long and 1/16 to 1/8 inch wide.
Fruit and Seed Characteristics
Fruit is leathery, oval, 1/2 inch long with 1 to 4 seeds and matures below the surface of the water. It rarely splits open to release seeds so that the main means of reproduction are stem fragments or special buds (turions) which grow into new plants.
The seed is roundish and narrows at each end resembling a spindle with yarn spun on it. Each seed is smooth, about 1/4 inch long and is topped by a firm, tapering tip about 1/4 inch long. When seeds are produced (which isn't often), they ripen underwater.