An erect, perennial herb 1-3 m. high with long, linear leaves sheathing at the base. The leaves typically do not extend above the spike. The flowers are packed into dense, cylindrical spikes, the upper portion consisting of the staminate flowers and the lower portion the pistillate flowers. The two portions of the spike are continuous or nearly so.
Fruit is a tiny, tufted nutlet.
In flower during May and June. Broad-leaved cattail is a persistent emergent found in almost all our wetland plant communities from deep marshes to open bogs, growing on wet substrates and often in one to two feet or more of standing water. It spreads extensively by rhizomes so that an acre of cattail may consist of only a few individual plants. Broad-leaved cattail can also form floating mats. Cattail stands provide important food and cover for wildlife.