Native or Introduced:
Nutrient Removal Rating:
Rooted or Floating:
Full sun to part shade
Maximum Water Depth:
Alligatorweed is a perennial aquatic herb that can sometimes be semi-terrestrial. It produces prostrate stems that grow laterally. Under certain conditions, the plant can be highly aggressive - leading to formation of dense, oppressive mats.
Stems are red-green and 1/4 inch in thickness.
Leaves lack petioles and are narrow and elliptical in shape. They are dark green with a lighter green midvein. Leaves are arranged opposite each other on the stem. Leaves are approximately 4 inches long.
Flowers are white and are grouped in spherical spikes that arise from leaf axils. They look similar to the white ball-like inflorescences of clover plants. The flowering season stretches from April to October.
Alligatorweed will grow in most areas where there is significant moisture. Typically it is found in lakes and streams. It may be present in small colonies of large thick mats that can cover entire bodies of water.