There are many species of spike rush and they are difficult to identify without using detailed botanical keys. In general, spike rushes are small (although some reach heights of 4 feet) perennial plants are often confused with the smaller species of rushes, grasses, or sedges. Slender spike rush can grow completely underwater and appear as a submerged plant.
Spike rushes can grow in shallow water or moist soils and grow from rhizomes. Stems are unbranched with sheaths around the base but can be round, square, or flattened depending on the species. All spike rushes have small fruiting spikes at the tips of the stem.
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. Docks, geese, muskrats, and nutria all eat portions of spike rushes, from seeds, to rhizomes and tubers.