Kuwai (Japanese: クワイ) is a Japanese plant whose underground stem (rhizome) is edible. It is a cultivar of Sagittaria trifolia. It has different common names in different regions of Japan.[1] The underground stems of this neighboring species are also eaten in China.
Kuwai and Chinese cígū (慈姑) are different cultivars, but both are treated as kuwai in Japan and cígū in China. The etymology of the Japanese name kuwai is uncertain.[2]