Three-square is a member of the bulrush family. Three-square is a perennial plant that forms dense colonies from rhizomes and can grow to 4 feet tall. It has few leaves, usually around the base. Stems are triangular in cross-section. Flowers are small spikes near the end of the stems (1 to 2 inches).
Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called “detritus”) for many aquatic invertebrates. Seeds are consumed by ducks while geese, muskrats, and nutria consume the rhizomes.