Limnophila aromatica, the rice paddy herb, is a tropical flowering plant in the family Plantaginaceae.

It is native to Southeast Asia, where it flourishes in hot temperatures and grows most often in watery environments, particularly in flooded rice fields.

The plant was introduced to North America in the 1970s due to Vietnamese immigration following the Vietnam War.

It can grow in flooded rice paddies during wet season but it grows best on drained but still wet sandy soil of harvested rice paddies for a few months after the rainy season ended.

[1] Limnophila aromatica is able to live completely submerged, and as such it is a popular aquarium plant.