Rotala indica 节节菜
Rotala indica is a species of flowering plant in the loosestrife family known by the common name Indian toothcup. It is native to Southeast Asia. This aquatic plant is best known as a popular aquarium plant and as a weed of rice fields. It is known as an introduced species and a weed in rice-growing regions in Congo, Italy, and Portugal, and California and Louisiana in the United States.