native to Eurasia and now common in eastern North America, grows 0.6 to 1.8 metres (2 to 6 feet) high on riverbanks and in ditches. It has a branched stem bearing whorls of narrow, pointed, stalkless leaves and ending in tall, tapering spikes of red-purple flowers. Purple loosestrife was introduced into North America early in the 19th century. It is now considered a noxious weed in many parts of the United States and Canada, where it forms dense colonies and crowds out native wetland vegetation that provides food and habitat for wildlife. Swamp loosestrife, water willow, or wild oleander (Decodon verticillatus) is a perennial herb native to swamps and ponds of eastern North America. |
