Native to South America this weed has spread along the Gulf, Atlantic and Pacific coasts of the United States. It grows in both aquatic and wetland ecosystems. It also is an agriculture weed growing on farmlands. Through stem fragments the plant can disperse through waterways. Nodes generate both roots and stems allowing it to reproduce itself from fragments.
The plant forms vine-like mats in waterways and in wetlands. The vines can grow out 3'. Aquatic forms of the plant have hollow stems; terrestrial forms have denser stems. Oblong leaves grow oppositely along the stems and are up to 4" long. In summer, small, white flowers grow at the point where the leaves meet the stem; flowers are reminiscent of clover.
Fact Sheet: Alligatorweed
Photo credits: Flower: Gary Buckingham, USDA Agricultural Research Service, Bugwood.org;
Mat: James H. Miller, USDA Forest Service, Bugwood.org