Alternanthera sessilis
 Alternanthera sessilis is an aquatic plant known by several common names including sessile joyweed and dwarf copperleaf. It is used as an aquarium plant.The plant occurs around the world.The leaves are used as a vegetable. Young shoots and leaves are eaten as a vegetable in Southeast Asia. Occasionally it is cultivated for food or for use in herbal medicines.This species is classified as a weed in parts of the southern States of the USA.