Causonis japonica(Thunb.) Raf.

bushkiller

WFO wfo-1200063020 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Causonis japonica, photographed by Luka S. (someplant)
fig. a Luka S. (someplant), CC0 1.0 / 2022-06-08 / obs. 204779134

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
Royal Botanic Gardens, Kew
Accession
K001639325
Filed as
Causonis japonica (Thunb. ex Murray) Raf.
Det. by
Trias-Biasi, A.
Collected
Briggs, M. ; Simbiak, V. ; Paiki, T. 2013-01-29
Origin
ID
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. We link to the digitised sheet rather than rehosting it, because the holding institutions do not serve their images to third parties reliably and we are not going to show you a picture we cannot actually deliver. 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 sheets never recorded a determiner, which is ordinary.

Native range 26 botanical countries

Regions where Causonis japonica is native: China North-Central, China South-Central, China Southeast, Hainan, Japan, Korea, Nansei-shoto, Ogasawara-shoto, Taiwan, Andaman Is., Assam, Bangladesh, Borneo, Cambodia, Christmas I., East Himalaya, India, Jawa, Laos, Malaya, Myanmar, Nepal, Nicobar Is., Sri Lanka, Thailand, Vietnam China North-CentralChina South-CentralChina SoutheastHainanJapanTaiwanAssamBangladeshBorneoCambodiaEast HimalayaIndiaJawaLaosMalayaMyanmarNepalSri LankaThailandVietnam KoreaNansei-shotoAndaman Is.Christmas I.Nicobar Is.
Native distribution of Causonis japonica, 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
Andaman Is. AND ASIA-TROPICAL
Assam ASS
Bangladesh BAN
Borneo BOR
Cambodia CBD
Christmas I. XMS
East Himalaya EHM
India IND
Jawa JAW
Laos LAO
Malaya MLY
Myanmar MYA
Nepal NEP
Nicobar Is. NCB
Sri Lanka SRL
Thailand THA
Vietnam VIE
China North-Central CHN ASIA-TEMPERATE
China South-Central CHC
China Southeast CHS
Hainan CHH
Japan JAP
Korea KOR
Nansei-shoto NNS
Ogasawara-shoto OGA
Taiwan TAI

Not drawn on the map: Ogasawara-shoto. 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 218 in flower of 424 examined

Proportion of examined Causonis japonica in flower, by month
Month In flower Examined Share 95% interval
Jan 6 18 33% 16% to 56%
Feb 7 14 50% 27% to 73%
Mar 14 22 64% 43% to 80%
Apr 22 38 58% 42% to 72%
May 20 52 38% 26% to 52%
Jun 18 39 46% 32% to 61%
Jul 32 48 67% 53% to 78%
Aug 32 54 59% 46% to 71%
Sep 38 64 59% 47% to 71%
Oct 20 46 43% 30% to 58%
Nov 4 17 24% 10% to 47%
Dec 5 12 42% 19% to 68%

Peak flowering in Jul. Each bar is the share of Causonis japonica 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. 218 of 424 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 1,915 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -1.3 °C 11.2 °C 15.0 °C
Warmest month, mean daily high 27.8 °C 29.9 °C 32.2 °C
Annual rainfall 1,341 mm 1,921 mm 3,927 mm
Rainfall in the driest quarter 69 mm 154 mm 635 mm

It is found where winters bring light 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 1,915 research-grade observations of Causonis japonica 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 27 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.

  • Causonis japonica Raf.
  • Cayratia japonica (Thunb.) Gagnep.
  • Cayratia japonica var. dentata (Makino) Honda
  • Cayratia japonica var. pseudotrifolia (W.T.Wang) C.L.Li
  • Cayratia japonica var. taiwaniana Masam.
  • Cayratia pseudotrifolia W.T.Wang
  • Cayratia trifolia var. quinquefoliola W.T.Wang
  • Cissus cyanocarpa Miq.
  • Cissus cymosa Steud.
  • Cissus japonica (Thunb.) Willd.
  • Cissus japonica var. dentata Makino
  • Cissus leucocarpa Blume
  • Cissus paniculata B.Heyne
  • Cissus tenuifolia var. cinerea Gagnep.
  • Cissus truncata M.A.Lawson
  • Cissus vagans Carrière
  • Columella japonica (Thunb.) Merr.
  • Columella japonica Craib
  • Columella japonica var. dentata (Makino) Masam.
  • Columella tenuifolia Merr.
  • Vitis cymosa Blume
  • Vitis irawadyana Steud.
  • Vitis japonica Thunb.
  • Vitis leucocarpa (Blume) Hayata

and 3 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. USDA PLANTS Database. common name, checklist symbol CAJA7. public domain. 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.