Causonis japonica

Causonis japonica is a perennial herbaceous vine with compound, alternately branching leaves. Tendrils grow opposite each leaf. The leaves have 5 leaflets with dentate margins and a white coloration on the lower surface. The leaflets are arranged in a semi-palmate arrangement with 2 pairs of 2 with 1 singular leaflet with a longer stem in the center. It flowers in the late summer with red, white, and yellow flowers developing in umbels and producing grape-like berries with 2-4 seeds.{{cite web|last1=Koepke-Hill, Armel|title=Bushkiller|url=https://extension.tennessee.edu/publications/Documents/W230.pdf|publisher=University of Tennessee Institute of Agriculture|access-date=1 November 2015}} In South Korea it flowers in July and August, with its fruit ripening in September and November, while in the southern hemisphere, in the Australian Northern Territory, it flowers and fruits in October.{{Cite web |title=Causonis japonica (Thunb.) Raf. var. japonica |url=https://eflora.nt.gov.au/factsheet?id=19330 |access-date=2025-03-02 |website=eflora.nt.gov.au}}

This species may be confused with Virginia creeper in that they both have leaves with 5 toothed leaflets, but Virginia creeper lacks a petiolule (stem connecting a leaflet to the main leaf stem) on any of the leaflets.{{Citation needed|date=March 2025|reason=Probably the texas reference but not given in the text}}

It is a vine which grows on the edges of rainforests.

As can be seen from the list of synonyms, this species has been named and renamed many times.

It was first described as Vitis japonica in 1784 by Carl Peter Thunberg from a specimen found near Nagasaki.{{APNI2|name=Causonis japonica|id=51358020|access-date=2025-03-02}}Thunberg, C.P. (1784), [https://www.biodiversitylibrary.org/page/51609427 Flora Japonica: 104] Its current name was given in 1838 by Constantine Samuel Rafinesque, when he transferred the species to the genus Causonis.Rafinesque, C.S. (1838), [https://www.biodiversitylibrary.org/page/19773299 Sylva Telluriana: 87]

in 1798, Carl Ludwig Willdenow transferred it to the genus Cissus, to give Cissus japonica.{{Cite web |title=Causonis japonica (Thunb.) Raf. {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:60470155-2 |access-date=2025-03-01 |website=Plants of the World Online |language=en}}Willdenow, C.L. (1798) in [https://www.biodiversitylibrary.org/page/629976 Species Plantarum Edn. 4, 1(2): 659] In 1918, Elmer Drew Merrill transferred it to the genus Columella.{{cite journal|author=Merrill, E.D. |date=1918|url= https://www.biodiversitylibrary.org/page/694811 |journal=The Philippine Journal of Science|volume=13|pages=145|title=Flora of the Loh Fau Mountain}} In 1911, François Gagnepain transferred it to the genus Cayratia, to give Cayratia japonica,{{cite journal|author=Gagnepain, F.|title=Cayratia|journal=Notulae systematicae (Paris) |volume=1|pages= 349| date=1911|url=https://www.biodiversitylibrary.org/page/4506898}} a name which was accepted by Australian authorities until at least 2020,{{Cite Q|Q107670400}}Brown, G.K. & Bostock, P.D. (December 2020), Appendix A: New names and name and status changes 2019 to 2020. Introduction to the Census of the Queensland Flora 2020: 19   and which remains its accepted name in South Korea.{{Cite web |title=국립생물자원관 한반도의 생물다양성 (NIBR: Cayratia japonica (Thunb.) Gagnep.) |url=https://species.nibr.go.kr/home/mainHome.do?cont_link=009&subMenu=009002&contCd=009002&pageMode=view&ktsn=120000062454 |access-date=2025-03-01 |website=species.nibr.go.kr}}

Causonis japonica has been introduced in tropical areas of the United States including Texas, Louisiana, Mississippi, Alabama, and North Carolina,{{cite magazine | url = http://www.se-eppc.org/wildlandweeds/pdf/Winter2011Spring2012-Matthews-pp6-8.pdf | title = Control of Cayratia japonica, Bushkiller, in an Urban Habitat in Charlotte, NC | last1 = Matthews | first1 = James | last2 = Marshall | first2 = Gary | last3 = Hodges | first3 = Michael | magazine = Wildland Weeds | date = 2012 | pages = 6–8 | publisher = Southeast Exotic Pest Plant Council}} where it is known as bushkiller. It can outcompete native plants and stress native trees by blocking sunlight and weighing them down. Controlling this weed is difficult as it can regenerate from rhizomes that remain in the soil. Cutting the stems at the ground and applying a systemic herbicide will often kill the plant. Composting it is not recommended as it can re-sprout from buried stems.

{{Reflist}}

• {{GRIN | accessdate=2009-07-18}}
• {{cite book |author1=Xinrong Yang |author2=Anmin Chen |author3=Bingyi Fu |title=Encyclopedic reference of traditional Chinese medicine| year=2003 |page=323| publisher=Springer }}

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• [https://www.gbif.org/species/4055350 Causonia japonica: images & occurrence data] from GBIF

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Category:Vitaceae

Category:Flora of Asia

Category:Flora of Queensland