A view of a typical mat of alligatorweed as it occurs in canals and drainage ditches and rice fields. Even though it does not produce viable seed in Louisiana, it flowers profusely, producing flowers at the end of a stalk (peduncle) that resemble somewhat the flowers of white clover.

The stem of alligatorweed is hollow which can be seen readily when cut in cross section. This probably helps the plant to float in water. Alligatorweed leaves are arranged opposite each other in two planes.