Oenanthe javanica (Blume) DC.

Common Name: Java waterdropwort

Synonyms and Other Names:

Oenanthe stolonifera Wall. ex DC., Oenanthe javanica ssp. javanica (Blume) DC., Oenanthe javanica ssp. stolonifera (Wall. ex DC.) Murata (ITIS 2022), Java water dropwort, water celery, water dropwort, seri, Japanese parsley, Chinese celery, sui-kan, pak chi lawm, shelum, and damoe



Copyright Info

Identification: O. javanica is an herbaceous perennial which grows up to nearly 2 meters and occasionally branches. Its stems are light green and hollow, with vertical veins (Illinois Wildflowers 2022) Its leaflets possess coarse toothlets and are sometimes slightly lobed and crinkled (iNaturalist 2022). Yatskievych and Raveill added the following details in their 2001 journal article: “Leaves are alternate and sometimes also basal, with blades 3-20 cm long  in ovate to triangular ovate in outline. Flowers number 5 to numerous in each umbellet with pedicels 1-5 mm long. Flowers possess 5 sepals with minute triangular teeth and 5 white petals that are obovate, appearing shallowly notched apically but narrowed abruptly to a slender pointed at the tip.”


Size: About 2m (Stephens 2018)


Native Range: The species is native to East Asia. 


This species is not currently in the Great Lakes region but may be elsewhere in the US. See the point map for details.

Table 1. States/provinces with nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Oenanthe javanica are found here.

State/ProvinceFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
DC199919991Middle Potomac-Anacostia-Occoquan
GA200720091Oostanaula
IL199820134Chicago; Des Plaines; Embarras; Upper Kaskaskia
MD200520051Middle Potomac-Anacostia-Occoquan
MN201620222Middle Minnesota; Twin Cities
MO199620001Blackwater
NH201520151Contoocook River
NJ201920203Middle Delaware-Musconetcong; Raritan; Sandy Hook-Staten Island
OH201820181Little Miami
VA200320132Middle Potomac-Anacostia-Occoquan; Middle Potomac-Catoctin
WI200120163Middle Rock; Milwaukee; Sugar

Table last updated 6/25/2024

† Populations may not be currently present.


Ecology: Oenanthe javanica is a perennial herbaceous plant that inhabits a variety of locales with saturated soils. This ranges from soggy meadows and muddy stream banks to marshes and lake shores (Illinois Wildflowers 2022). It possesses no discernable preference for substrate type or inherent nutrient availability and will also grow without rooting itself to substrate(Chang et al. 2012, Barco and Borin 2020). It will tolerate a variety of light availability conditions but seems to prefer semi-shaded habitat (Misako et al. 1987). The pH preference of the species skews slightly acidic but it will tolerate a range of pH levels from about 5-8 (Choi et al. 2012, Plants for a future 2022). Additionally, the species is known to buffer soil pH, ensuring that pH levels remain within a narrow range around neutral (Xin et al. 2012). Finally, the species can grow in a range of climatic conditions, as its native habitats include both tropical and temperate regions and it has also been introduced to colder climates in areas like Minnesota and Wisconsin, where the species has been observed overwintering (iNaturalist 2022, Seely 2011, Invasive Plant Atlas 2018).

The species can reproduce via sexual reproduction but more commonly reproduces via vegetative fragmentation. Broken fragments of the plant disperse via water currents and will take root downstream, allowing the species to spread quickly (Bowen 2020).


Great Lakes Means of Introduction: Oenanthe javanica has a high probability of introduction to the Great Lakes (Confidence level: Moderate).


Potential pathway(s) of introduction: Dispersal, hitchhiking, unauthorized intentional release, escape from recreational culture.

There are several means of introductions for O. javanica. Viable fragments of the species can disperse on water currents or get caught on boat trailers and other water gear (Bowen 2020). The species is also available for sale in specialty supermarkets and in some cases cultivated for commercial sale or its phytoremediation potential, creating the possibility that viable individuals may escape from personal gardens of individuals (Morton and Snyder 1978, Hargis 1998). Additionally, the species is available for purchase and has uses in the aquarium trade, increasing the potential that individual plants will escape outdoor water gardens or owners will intentionally release plants into the basin.


Great Lakes Status: The species is currently not present in the Great Lakes below the normal high water mark. It has been confirmed to be within 20km of the basin as recently as 2011 (Seely 2011).  O. javanica is already in the Great Lakes region, with confirmed sightings in Wisconsin, Illinois, and Minnesota (Invasive Plant Atlas 2014, Illinois Wildflowers 2022). Reported but unconfirmed sightings have placed the species in the basin (BONAP 2014), but not below the ordinary high water mark. Due to its ubiquity in the aquarium trade and popularity it is possible that the species is regularly planted within the Great Lakes basin.

Oenanthe javanica has a moderate probability of establishment if introduced to the Great Lakes (Confidence level: High).

The temperate portions of O. javanica’s native range share similarities with the Great Lakes basin. However, the Great Lakes basin typically endures longer periods of freezing temperatures. O. javanica is a frost tolerant species and has been recorded overwintering in Wisconsin (Seely 2011). Additionally, the species is tolerant to a variety of biotic and abiotic conditions which aid its establishment potential.

Increasing temperatures associated with climate change will likely benefit the species by increasing its growing season and ability to overwinter. Increased salinization likely won’t impact the species, as it has been documented growing in water with salinity concentrations of 3.6 ppm (Kumar et al. 2020).


Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...

EnvironmentalSocioeconomicBeneficial



Oenanthe javanica has the potential for moderate environmental impact if introduced to the Great Lakes.

Oenanthe javanica is susceptible to sclerotinia rot caused by Sclerotinia sclerotiorum which it can pass from host to host (Kwon et al. 2003). Over 1400 species worldwide are susceptible to sclerotinia rot. The species has also been identified as a second intermediate host of fascioliasis causing species (aka liver flukes), which primarily impacts ungulates but can infect humans as well (Choi et al. 2015). The species has been found to have allelopathic effects on strains of Microcystis spp. (Zhao et al. 2013, Zhang et al 2015). While literature does not explicitly state that the species will outcompete native species in the Great Lakes Basin, it has been noted as a dominant macrophyte in India and formed a monoculture in a Wisconsin drainage ditch (Seely 2011, Devi and Singh 2016). The species also inhibited the growth of two Microcystis spp., demonstrating its allelopathic potential (Zhang et al. 2015). Furthermore, the species is likely to alter the hydrology of small streams when it does form dense mats. This may alter stream flow, disturb the air-to-water interface and reduce dissolved oxygen levels, and alter predator-prey interactions.

Oenanthe javanica has the potential for moderate socioeconomic impact if introduced to the Great Lakes.

O. javanica is sold commercially through specialty supermarkets and aquarium stores. The species is also a carrier for several harmful species of bacteria such as Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus (Kim et al. 2014). This creates the potential for humans to contract various illnesses associated with the aforementioned species. This species is also used in the phytoremediation of wastewater and heavy metals. However, if individual plants which have bioaccumulated heavy metals aren’t removed from the ecosystem, those metals may be released back into the environment when the older roots and shoots decay (Zhou and Wang 2010).

Oenanthe javanica has the potential for high beneficial impact if introduced to the Great Lakes.

Environmental engineers frequently include O. javanica in floating wetland and other natural phytoremediation systems due to its ability to bioaccumulate phosphorus and nitrogen while lowering levels of chemical oxygen demand (Chen et al. 2017, Du et al. 2018, Du et al. 2020, Gao et al. 2020, Sun et al. 2021, Gao et al. 2022). The species will also bioaccumulate various heavy metals, such as cadmium, copper, lead, and zinc but some studies suggest that bioaccumulating these heavy metals negatively impact the growth of O. javanica (Deng et al. 2006, 2009, Dong et al. 2016, Zanin et al. 2018, Liu et al. 2020).

The species is also sold in specialty supermarkets and aquarium stores, thus contributing to local economies.

The species also possesses significant research value as scientists have begun to study O. javanica, which has a long history of use as a medicinal herb. Traditionally used to treat inflammation and fevers, recent studies have demonstrated the potential for O. javanica extracts to be used in treatments for Parkinson’s, UVB ray exposure, tetrodotoxin poisoning,  and various chronic health conditions (Kim et al. 2009, Kim et al. 2013, Ku et al. 2013, Ku et al. 2013, Chan et al. 2017, Her et al. 2019, Jang et al. 2019, Gam et al. 2022).

Ecologically, the species is a preferred plant for the oviposition of Dytiscus sharpi eggs and may have beneficial effects for native diving beetles (Inoda 2011).


Management: Regulations (pertaining to the Great Lakes region)

The species is not on the Illinois Aquatic Life Approved Species List and if it is not otherwise native to Illinois it is illegal to be imported or possessed alive without a permit (515 ILCS 5/20-90).

It is a prohibited species in Wisconsin and one cannot transport, possess, transfer, or introduce this species without a permit (Chapter NR 40, Wis. Adm. Code).

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control

Biological
There were no identified biological controls for O. javanica in the literature review. However, the species is susceptible to sclerotinia rot which it contracts from Sclerotinia sclerotiorum which causes death of leaves, reducing the fecundity of the plant by reducing the ability of the plant to spread via fragmentation (Kwon et al. 2003).

Physical

Physical control methods focus on the hand pulling of small infestations. Some literature has suggested controlling larger infestations with “puddling”, that is tilling sections of soil and burying O. javanica under a layer of soil that is at least 2 cm deep in order to reduce the sprouting of individuals (Okuma et al. 1980).

Chemical

This review found no evidence of specific herbicides or other chemical control methods in use to control O. javanica and other risk assessments corroborated this (MISIN 2022).

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.


References (click for full reference list)


Author: I. Pfingsten, D. Rose


Contributing Agencies:
NOAA GLRI Logo


Revision Date: 12/16/2022


Citation for this information:
I. Pfingsten, D. Rose, 2024, Oenanthe javanica (Blume) DC.: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?HUCNumber=DGreatLakes&Potential=Y&Species_ID=3046&Type=2, Revision Date: 12/16/2022, Access Date: 6/27/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.