water parsley

Oenanthe sarmentosa is a species of flowering plant in the carrot family known by the common name water parsley. It is native to western North America from Alaska to California, where it grows in wet areas, such as streambanks. It is sometimes aquatic, growing in the water. The plant has been used in cultivation in wetlands, and the recent discovery of several colonies growing by a stream in Illinois demonstrates its capacity to become a noxious...