Oenanthe javanica aka Chinese Celery

Oenanthe javanica is a low plant in the carrot family. It is a perennial, which means it lives for years. Names include Java waterdropwort, water celery, and Chinese celery. It is native to much of Asia and northern Australia. Its range starts in southeastern Siberia. It extends through tropical and subtropical parts of Asia. It grows by lakes, streams, and ponds, and in marshes. It also grows in wet meadows and ditches. Damp forest edges provide another home for this plant. It now grows wild in Missouri, where it has become established.

Garden plants grow about 0.75–2.5 feet (0.23–0.76 m) tall. They can spread to 3 feet (0.91 m) wide. Useful Tropical Plants gives a wider range for height: 0.3–4.9 feet (0.1–1.5 m). The roots are fibrous, and stems lean along the ground. Creeping stems called stolons root at joints called nodes. These stems spread fast and can form large clumps. Over time, they can also form groups called colonies. Seeds that fall near the plants help them spread too.

White flowers bloom from July to September. They add interest to wet beds and pond edges. Insects pollinate the flowers by moving pollen between them. The plant is self-fertile: its own pollen can form seeds. Missouri Botanical Garden notes that full sun brings more flowers. The supplied evidence says little about this species' fruit shape. People in parts of Asia eat young leaves and stems. They eat them raw or cooked, and put leaves in soups. The taste is like carrot or parsley. People also eat cooked roots; reports list seeds as edible.

Grow this plant in moist to wet soil. It accepts full sun or part shade and tolerates wet ground. It can grow in shallow pond water too. Missouri Botanical Garden lists USDA hardiness zones 3–9. It suits bog gardens, rain gardens, and damp woodland clearings. It also serves as ground cover by water or in containers. Rich, moist soil can make its spread hard to control. Managing that spread is a key part of garden care. Missouri Botanical Garden reports no serious pest or disease problems.

Raise plants by spring division, layering, or stem-tip cuttings. These methods split plants or root stems to make new ones. Stem pieces root with ease, but seeds may sprout unevenly. Records of past use as medicine include treating fever. These reports do not show that such treatments are safe. PFAF found no specific report that this species is toxic. It still urges care: some related species are very poisonous. This plant's food uses do not mean every waterdropwort is edible.