Oenanthe javanicaDC.

Java waterdropwortWater Dropwort

WFO wfo-0000384719 Accepted WFO 2026-06 8 photographs CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Oenanthe javanica, photographed by chiuluan
fig. a chiuluan, CC BY 4.0 / 2022-05-20 / obs. 199739024

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
Smithsonian, US National Herbarium
Accession
US 3441719
Filed as
Oenanthe javanica (Blume) DC.
Det. by
Yatskievych, G. A.
Collected
R. H. Simmons 2003-08-02
Origin
US
The sheet
View the digitised specimen (CC0 1.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 35 botanical countries

Regions where Oenanthe javanica is native: China North-Central, China South-Central, China Southeast, Chita, Hainan, Inner Mongolia, Japan, Korea, Kuril Is., Manchuria, Mongolia, Nansei-shoto, Primorye, Sakhalin, Taiwan, Assam, Bangladesh, Borneo, Cambodia, East Himalaya, India, Jawa, Laos, Lesser Sunda Is., Maluku, Myanmar, Nepal, New Guinea, Pakistan, Philippines, Sulawesi, Sumatera, Thailand, Vietnam, West Himalaya China North-CentralChina South-CentralChina SoutheastChitaHainanInner MongoliaJapanManchuriaMongoliaPrimoryeSakhalinTaiwanAssamBangladeshBorneoCambodiaEast HimalayaIndiaJawaLaosLesser Sunda Is.MalukuMyanmarNepalNew GuineaPakistanPhilippinesSulawesiSumateraThailandVietnamWest Himalaya KoreaNansei-shoto
Native distribution of Oenanthe javanica, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Assam ASS ASIA-TROPICAL
Bangladesh BAN
Borneo BOR
Cambodia CBD
East Himalaya EHM
India IND
Jawa JAW
Laos LAO
Lesser Sunda Is. LSI
Maluku MOL
Myanmar MYA
Nepal NEP
New Guinea NWG
Pakistan PAK
Philippines PHI
Sulawesi SUL
Sumatera SUM
Thailand THA
Vietnam VIE
West Himalaya WHM
China North-Central CHN ASIA-TEMPERATE
China South-Central CHC
China Southeast CHS
Chita CTA
Hainan CHH
Inner Mongolia CHI
Japan JAP
Korea KOR
Kuril Is. KUR
Manchuria CHM
Mongolia MON
Nansei-shoto NNS
Primorye PRM
Sakhalin SAK
Taiwan TAI

Not drawn on the map: Kuril Is.. We hold no public-domain boundary for this region, so it is listed rather than guessed at.

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 235 in flower of 292 examined

Proportion of examined Oenanthe javanica in flower, by month
Month In flower Examined Share 95% interval
Jan 6 7 86% 49% to 97%
Feb 11 15 73% 48% to 89%
Mar 48 55 87% 76% to 94%
Apr 89 99 90% 82% to 94%
May 22 36 61% 45% to 75%
Jun 6 10 60% 31% to 83%
Jul 15 19 79% 57% to 91%
Aug 16 18 89% 67% to 97%
Sep 9 12 75% 47% to 91%
Oct 5 11 45% 21% to 72%
Nov 4 5 80% 38% to 96%
Dec 4 5 80% 38% to 96%

Peak flowering in Apr. Each bar is the share of Oenanthe javanica observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 235 of 292 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 2,013 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -9.1 °C 10.6 °C 14.5 °C
Warmest month, mean daily high 21.6 °C 28.9 °C 31.2 °C
Annual rainfall 883 mm 3,655 mm 4,650 mm
Rainfall in the driest quarter 75 mm 448 mm 823 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 2,013 research-grade observations of Oenanthe javanica that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 32 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Cyssopetalum javanicum (Blume) Turcz.
  • Dasyloma corticatum Miq.
  • Dasyloma japonicum Miq.
  • Dasyloma javanicum (Blume) Miq.
  • Dasyloma laciniatum (Blume) Miq.
  • Dasyloma latifolium Lindl.
  • Dasyloma subbipinnatum Miq.
  • Falcaria javanica (Blume) DC.
  • Falcaria laciniata (Blume) DC.
  • Oenanthe alatinervis Y.Y.Qian
  • Oenanthe australiana F.Muell.
  • Oenanthe corticata Edgew.
  • Oenanthe decumbens Koso-Pol.
  • Oenanthe decumbens var. laciniata (Blume) Koso-Pol.
  • Oenanthe japonica (Miq.) Drude
  • Oenanthe javanica f. rosea Hayashi
  • Oenanthe javanica subsp. stolonifera (DC.) Murata
  • Oenanthe javanica var. japonica (Miq.) Honda
  • Oenanthe kudoi Suzuki & Yamam.
  • Oenanthe laciniata (Blume) Zoll.
  • Oenanthe normanii F.P.Metcalf
  • Oenanthe pterocaulon Liu, C.Y.Chao & Chuang
  • Oenanthe rosthornii Diels
  • Oenanthe schlechteri H.Wolff

and 8 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.