Zizania latifolia aka Manchurian Water Rice

Zizania latifolia is a water grass in the Poaceae family. Common names include Manchurian wild rice and water rice. Its native range extends from Assam to southeastern Siberia. It also grows across temperate eastern Asia. It is not native to Britain or Ireland. This plant grows in marshes, swamps, and shallow lake edges. It can form large patches in these wet sites.

This grass is a perennial with underground rhizomes. One source also describes plants that grow as annuals. Plants reach about 4–8 feet [1.2–2.4 metres] tall. Other accounts give a height of 11.5 feet [3.5 metres]. Gardeners grow it beside ponds and along lake shores. Its stands provide cover for wildfowl. People also grow it as an ornamental water plant. Its leaves have a practical use in woven mats.

Flowers appear from July to September, according to Plants For A Future. Seeds ripen during the same months. Plants seldom flower in Britain, despite reports of good growth there. Cooked seeds serve as a grain in sweet or savoury dishes. People also grind the seeds into flour for baking. The listed edible parts include flowers, roots, shoots, and stems. East Asian growers raise this species as a food crop. Chinese cooks also use stem bases swollen by a smut fungus. They harvest these before the fungus forms spores and spoils the flesh.

Grow this plant in shallow water that stands or moves slowly. It grows well in sun and can also take partial shade. It accepts sandy, loamy, and clay soils. Slightly acid clay loam suits it best. It also tolerates neutral and mildly alkaline soil. Warm summers help it grow well. Reports place its preferred summer warmth at 20–30°C. Sources disagree on frost limits, so a firm hardiness rating is uncertain. Some report winter survival in England and Beijing.

Fresh seed must stay wet, as dry seed soon loses viability. Sow it in spring, with the pots under shallow water. Plants can also be divided in spring. Plants For A Future lists no known hazards. It records traditional medicinal uses for shoots, roots, seeds, and leaves. These records do not establish medical safety or benefit. The supplied evidence gives no broader account of pests or diseases.