Zizania latifolia

About

Zizania latifolia, known as Manchurian wild rice, is the only member of the wild rice genus Zizania native to Asia. It is used as a food plant. Both the stem and grain are edible. Gathered in the wild, Manchurian wild rice was an important grain in ancient China. A wetland plant, Manchurian wild rice is now very rare in the wild, and its use as a grain has completely disappeared in Asia, though it continues to be cultivated for its stems. A measure of its former popularity is that the surname Jiǎng, one of the most common in China, derives from this crop.

Summary from Wikipedia