The swollen crisp white stems of Manchurian wild rice are grown as a vegetable, popular in East and Southeast Asia. The swelling occurs because of infection with the smut fungus "Ustilago esculenta". The fungus prevents the plant from flowering, so the crop is propagated asexually, the infection being passed from mother plant to daughter plant. Harvest must be made between about 120 days and 170 days after planting, after the stem begins to swell, but before the infection reaches its reproductive stage, when the stem will begin to turn black and eventually disintegrate into fungal spores.