It is native to Asia (China, India, Russia, Japan, Malaysia, etc.

[3] The hairless, branching stems may root at lower nodes that come in contact with the substrate.

The inflorescence is an elongate cluster up to 8 centimeters (3.2 inches) long and contains many pink flowers.

[5] In its native region this plant is a common weed of rice paddies.

It can be found in meadows, marshes, mudflats, riverbanks, floodplains, levees, and lowland and upland forests.