Sparganium emersum is a species of flowering plant in the cat-tail family known by the common names European bur-reed and unbranched bur-reed. It has a circumboreal distribution, occurring throughout the northern latitudes of Eurasia and North America. It is an aquatic plant, growing in shallow water bodies such as ponds and streams. It can become abundant at times. It is a perennial herb producing a floating stem up to 2 meters long. The leaves may be... (Wikipedia)