Sparganium natans is a species of bur-reed known by the common names least bur-reed and small bur-reed. It is a water plant native to high elevation lakes and marshes of Canada and the northern United States. It is usually found submersed in shallow, calm water. This bur-reed has thin, flexible, grasslike leaves which float in the water. Plants that spend more time out of water at the waterline are tougher and have shorter leaves.