Java Waterdropwort or Vietnamese parsley
Known by a range of names, Java waterdropwort is often grown as a ground cover plant, particularly in areas of wet soil or along ponds and streams. It tends to spread rapidly by sending out runners that easily take root in wet soils.
OverviewOther names for this plant include:
- Common names: Vietnamese parsley, Japanese parsley, Chinese celery, water celery
- Scientific names: Oenanthe stolonifera
- This easily spreading ground cover plant can quickly move into wetlands and choke streams if released in or adjacent to natural areas.
Classification in Wisconsin: Prohibited
Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for Java waterdropwort was based upon this literature review [PDF] developed by the department.
Leaves: Lush green pinnate leaves resemble large flat parsley or celery foliage. A popular cultivar ‘Flamingo’ has white to pink edges to the leaves.
Flowers: Tiny white flowers bloom in umbels at the ends of stalks in late summer/early autumn.
Fruits & seeds: Similar to other members of the carrot family they form small oval seeds at the top of the flowering stalks. Controlling the seed heads will not prevent this plant from spreading.
Roots: Fibrous roots that can form from parts of stem touching the ground or in water.
Stems: The jointed stems are hollow and often grow spreading along the ground. They are fairly brittle and can break off easily and take root.
Similar species: Very similar in appearance and habit to bishop's weed (Aegopodium podagraria); a similarly invasive ground cover plant. In general, there are many white-flowered look-alikes in the parsley family. One example is Queen Anne’s lace (Daucus carota; non-native), a widespread weed in Wisconsin, with fern-like leaves, but leaves and stems are hairy. When crushed, it smells like carrots. Other look-alikes include wild chervil (Anthriscus sylvestris; invasive), caraway (Carum carvi; non-native), poison hemlock (Conium maculatum; invasive), Chinese hemlock parsley (Conioselinum chinense; native), native sweet cicely (Osmorhiza spp.).
See the reported locations of Java waterdropwort in Wisconsin.
Do you know of additional populations? Send us a report.
Mechanical: Cutting is unlikely to be effective and may contribute to the spread of this plant as it can take root from stem fragments that contain nodes. Pulling small populations may work if all roots and stem fragments are collected and disposed of.
Chemical: Aquatic formulas of translocating herbicides may provide some control. Care should be taken to avoid spraying non-target vegetation and a permit may be required.
View Java waterdropwort pictures in our photo gallery!
ResourcesSources for content:
- Efloras.org Flora of China - Oenanthe javanica [exit DNR].
- University of Florida extension Water Celery Factsheet [exit DNR].