Limnocharis flava (commonly known as yellow velvetleaf,[2] sawah flower rush, sawah lettuce[3]) is a species of aquatic flowering plant which is native to Mexico, Central America, South America, Cuba, Haiti and the Dominican Republic but widely naturalized in southern and southeastern Asia: India, Sri Lanka, Cambodia, Burma, Thailand, Vietnam, Indonesia, Malaysia, Brunei and southern China (Guangdong, Yunnan).

Its inflorescences have a very characteristic shape, producing three-lobed yellow flowers about 1.5 cm in diameter.

[5][6] Yellow velvetleaf grows generally wherever there is not very deep stagnant fresh water, in swampy areas.

[4][7] Traditionally this plant is an important vegetable in parts of Indonesia, the Philippines, Vietnam,[8] Laos, Isan (Thailand)[9] and parts of India, where the central flower stalk and the leaves are used in soups, curries, salads and stir-fries.

This characteristic was put into song by Muhammad Arief, in the 1940s hit Genjer-genjer in the Banyuwangi language in Java.