Water celery is also known as water dropwort, seri, sui-kan, pak chi lawm, shelum, and damoe. It is a perennial herb with creeping stolons and long, threadlike, white rootlets. The erect, slender, hollow, green stems range from 4 inches to 5 feet high. The deep green leaves, having an odor like carrot tops, resemble celery in shape and size. Tiny, white, fragrant flowers form in compound umbels of 10 to 25 blooms.
The plant grows wild in freshwater marshes and swampy fields, and along ditches, canals, and streams in many Asian countries. It is also cultivated there and in Hawaii.
It has been grown in Florida on a trial basis. To prevent its establishment as an aquatic weed pest, one must obtain a permit from the Florida Department of Natural Resources to grow it. In a test planting at Belle Glade in December 1977, sprigs were set out 9 inches apart in a concrete tank of flooded muck soil. It withstood temperatures as low as 31°F and by March had spread over a large area of the tank.
Several cuttings of leafy stalks were made periodically every 2 or 3 weeks. The flavor and tenderness were acceptable to Asian customers. There was a tendency for the planting to become densely matted after several cuttings, indicating a need to remove shoots and roots along with the tops. Almost no pests were observed on the test plantings.
The tops are eaten raw in salads or as a garnish similar to parsley. The young stems and leaves are also steamed with rice, or boiled and chopped as greens. There are many Asian recipes that include this vegetable.