Talk:Reynoutria japonica

History
The following is just rough background knowledge, not substantiated: it was brought into the UK around the Victorian era as a decorative plant in gardens. It's spread quickly to most parts of the country, grows on railway embankments, roadsides, motorway verges. In the UK climate at least it's very vigorous, and regarded in the UK as a pest; apparently it's one of only 2 plants whose propagation is forbidden by law. -- Tarquin

I've removed:
 * in the mid-1800's, and to the U.S. in the late 1800's.

because such precision makes me wonder if the writer means the 19th century or the decade of the 1800s. -- Tarquin 09:46 Jan 6, 2003 (UTC)

That quote clearly looks to be about a century period, not a decade. 69.87.203.190 20:29, 21 December 2006 (UTC)

So British
The species is a frequent invader in Europe and the U.K.

Is the British island forms part to the American continent? Plate tectonics? ;) Pixeltoo 15:14, 8 August 2005 (UTC)

grow on windowsill
What is the best way to raise shoots indoors for consumption year-round? 69.87.200.9 20:40, 19 November 2006 (UTC)

What growing conditions (temp/light etc) make it sprout? Make it die back? Keep it dormant? 69.87.194.175 21:20, 21 November 2006 (UTC) japanese knotweed is the best plant a baby panda could play with so if you own a zoo give that new panda a japanese knotweed

Probably best not to try. Really expensive if it spreads to your garden can be tens of thousands of pounds to remove, or off your house price, and improper disposal is illegal in the UK. —Preceding unsigned comment added by 82.44.68.212 (talk) 17:31, 28 September 2010 (UTC)

Question about link provided
Back in 2003 when I edited this page I added a link to a website that I had created (http://www.knottybits.com/knotweed). This appears to be in conflict with Wikipedia's current editing policy so I just want to put it out there in case someone wants to review the external links and decide whether my website should be deleted. Urtica 05:24, 21 August 2007 (UTC)


 * I wouldn't worry about it. The site seems informative and not WP:SPAM.  My experience with WP:LINKS is that people periodically go around and trim out external links, and that might happen to this one (the criteria have a moderate degree of subjectivity, and external links are expected to come and go).  But I don't think it should be a factor (in this case) that it was added by you instead of someone else. Kingdon 12:14, 21 August 2007 (UTC)

WikiProject Food and drink Tagging
This article talk page was automatically added with WikiProject Food and drink banner as it falls under Category:Food or one of its subcategories. If you find this addition an error, Kindly undo the changes and update the inappropriate categories if needed. The bot was instructed to tagg these articles upon consenus from WikiProject Food and drink. You can find the related request for tagging here. Maximum and careful attention was done to avoid any wrongly tagging any categories, but mistakes may happen... If you have concerns, please inform on the project talk page -- TinucherianBot (talk) 22:17, 3 July 2008 (UTC)

"Invasive species" opening sentence
I have restored the sentence to say "weed" rather than "green waste". I have no reason to doubt that Japanese knotweed is a large source of green waste, but that is a different topic. This paragraph is about the undesirable aspects of the plant. Spiel496 (talk) 16:27, 7 July 2008 (UTC)


 * Japanese knotweed is not considered as green waste because it will readily re-grow from cuttings. The very first line of the green waste article says "Green waste is biodegradeable...". This is not the case with knotweed, which is considered a controlled waste. To quote the Royal Horticultural Society (Gardening advice), which refers to digging up the plant: "This method also creates problems over disposal as Japanese knotweed is classed as 'controlled waste' under the Environmental Protection Act 1990. This requires disposal at licensed landfill sites." The plant can re-grow from pieces of stem (eg by cutting or flailing), crown or rhizome (from Birmingham Council knotweed info).


 * You can also refer to Suffolk Coastal District Council's page - 'Do not try to recycle Japanese knotweed'.


 * The case study reference you use to support your claim that knotweed is green waste is not specific enough. To quote: "We provided suitably trained manpower, equipment and transportation, to segregate the Knot Weed from any other vegetation and disposed of accordingly. The green waste was sent for composting, in order that our client complied with their environmental responsibilities." The knotweed was segregated and disposed of, and the green waste was sent for composting. They are two separate things. More importantly, your reference does not specifically say knotweed is green waste. Beechhouse (talk) 11:48, 12 July 2008 (UTC)

Commercial links
References 8,9 and 11 appear to be links to sellers of this product.Ykral (talk) 11:08, 29 January 2009 (UTC)

Commercial links2
Three more commercial links removed. Tompow (talk) 12:15, 13 August 2009 (UTC)

Cost of control in UK
The figure of £1.6 billion annually has been added, citing the Daily Mail. This size of this figure is not credible. This is more than the annual budget Environment Agency. --FDent (talk) 16:45, 14 July 2013 (UTC)

Correct Name
Is there any confusion in the name? Fallopia convolvulus (L.) A.Love (Polygonum convolvulus L.) seems to be confused here. Is F.japonica a different species? Osborne 20:58, 21 March 2014 (UTC)

Reynoutria japonica (Polygonum cuspidatum) is indeed a different species from Fallopia convolvulus. In Webbs Irish Flora (1996) the key notes: Annual, with twining stem....Fallopia. Perennial, with stout, erect stems...Reynoutria..Osborne 18:57, 22 March 2014 (UTC)

Webb, D.A., Parnell, J. and Doogue, D. 1996. An Irish Flora. Dundalgan Press, Dundalk. ISBN 0-85221-131-7

Is the Japanese "itadori" spelling correct? I believe it should be 虎杖 - appears someone changed it to "dead infant" which I can't find support for. — Preceding unsigned comment added by 2600:1000:B10B:245C:9DF:D65D:52EC:7BED (talk) 16:41, 17 August 2015 (UTC)
 * That appears to have been vandalism that is now corrected. Deli nk (talk) 17:14, 17 August 2015 (UTC)

Missing Citation
Hello all,

The following fact is missing a citation / reference: "The leaves are broad oval with a truncated base, 7–14 cm long and 5–12 cm broad"

I suggested this reference: https://www.japaneseknotweed.co.uk/japanese-knotweed-identification

There was a COI there so one of the editors kindly gave me a few Wiki etiquette pointers. Anyhoo, my question is this; Japanese Knotweed Lts are genuinely experts in their field, so does this warrant being a reference or does the fact that the website is commercial mean that it's not appropriate?

Next question, where would I find a more suitable reference if this one is deemed inappropriate?

Thanks, team! PaddyPassionDigital (talk) 15:54, 2 June 2014 (UTC)

(sorry if I mess up anything I haven't edited wiki in a while) The fifth citation is no longer valid, as it seems the domain has gone up for sale. and it thus needs replacing. — Preceding unsigned comment added by 96.237.189.150 (talk) 17:37, 7 June 2015 (UTC)


 * Well done PaddyPassionDigital for playing by the rules - it's appreciated. In a case like this where this information is widely available, why not refer to one of the existing references on the page, or just go to a non-commercial source to find the reference you need? There are plenty of places with no commercial interest where such a description can be found, here's one for a start: http://www.rhs.org.uk/advice/profile?PID=218 Naturenet | Talk 21:51, 2 June 2014 (UTC)

Thanks, Naturenet. I've updated the reference to the one you suggested :) PJone (talk) 10:39, 6 June 2014 (UTC)

Taxonomy & name
This species is widely known as Polygonum cuspidatum (and that name redirects to this page), but it appears nowhere in the article and there is no discussion of the taxonomy or alternative names in the article. 160.111.254.17 (talk) 20:12, 5 July 2016 (UTC)
 * Polygonum cuspidatum is a synonym of Reynoutria japonica the currently accepted name of the species, of which Fallopia japonica is also a synonym. A list of some other synonyms is given in the taxobox. You can find more information on The Plant List at http://www.theplantlist.org/tpl1.1/record/kew-2428745 Plant surfer  21:18, 5 July 2016 (UTC)

it's an interesting question as to whether Reynoutria japonica is the currently accepted name of the species. The facts seem clear (and are summarized in the Discussion section of this 2013 article). Recent molecular phylogenetic studies have established that there's a clade, the "RMF" clade, made up of Reynoutria, Muehlenbeckia and Fallopia subclades. There are then two choices: It's not clear at present, I think, which of these approaches will be most persuasive to taxonomists in the long run.
 * treat the subclades as three genus, including Fallopia sensu stricto, in which case Japanese Knotweed is Reynoutria japonica
 * treat the subclades as a single genus, Fallopia sensu lato, with three sections, in which case Japanese Knotweed is Fallopia japonica, placed in Fallopia sect. Reynoutria.

The Taxonomy sections of relevant articles need some work. Peter coxhead (talk) 09:45, 23 September 2016 (UTC)


 * I grant you that it is not over until the fat lady sings, but we need to stop somewhere, and TPL seems to be a reliable source. I think we should be reflecting the views of some stable, reliable source, even if it errs on the conservative side, rather than attempting to follow the swings and roundabouts of current research. Plant surfer  16:37, 23 September 2016 (UTC)
 * I agree with erring on the conservative side, but in this case it's not so clear what that is, since it was moved from Fallopia to Reynoutria and it's this move that some are resisting. However, I do agree that in cases of doubt we should follow TPL, which would suggest that the article should be moved to Reynoutria japonica. Peter coxhead (talk) 16:47, 23 September 2016 (UTC)


 * I know some people are reluctant to see the name change, but TPL is our reliable source, and the taxonomy has been changed for a while now. This article needs moving to Reynoutria japonica, and the other articles also adjusted according to TPL's taxonomy. Invertzoo (talk) 01:39, 21 July 2017 (UTC)


 * Do we hava a reasonable consensus on the proposed move? It sounds like perhaps we do? But I will not act on this until a few days have gone past. I lhae also left a note on the Plant Project talk page about this suggested move. Invertzoo (talk) 09:56, 21 July 2017 (UTC)
 * I'm now less convinced that the TPL approach should be followed, but I'd like time to review the literature a bit more before expressing my view. Peter coxhead (talk) 08:31, 22 July 2017 (UTC)
 * OK, please do check the sources -- apparently TPL has recently been updated and no longer uses pre-2013 sources. Thanks. Invertzoo (talk) 11:02, 22 July 2017 (UTC)
 * Really? The website still says 2013. Is there a new one? Peter coxhead (talk) 19:10, 22 July 2017 (UTC)
 * Let me check with my expert and see what says about this. Invertzoo (talk) 12:17, 23 July 2017 (UTC)


 * I should be able to get back to you within a couple of days. Invertzoo (talk) 01:50, 24 July 2017 (UTC)

Back again
TPL does have it listed as Reynoutria japonica:

http://www.theplantlist.org/tpl1.1/record/kew-2428745

Invertzoo (talk) 16:43, 6 September 2017 (UTC)
 * Um, but TPL has not been updated, and the source, WCSP (in review), isn't available. So we're no further forward, I think. Peter coxhead (talk) 17:17, 6 September 2017 (UTC)

hollow stems, water-filled
There are reports that the hollow stem is sometimes "water-filled", at least the lower above-ground part. If this is true, it seems worth mentioning in the article.-71.174.180.38 (talk) 22:31, 13 September 2016 (UTC)
 * Hmmm. What reports would these be? The criterion for inclusion in Wikipedia is that the statement is supported by a reliable source. Plant surfer  22:42, 13 September 2016 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 2 one external links on Fallopia japonica. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Corrected formatting/usage for http://www.bsbi.org.uk/BSBIList2007.xls
 * Added tag to http://www.gardenroots.co.uk/content.php?8-Japanese-knotweed-costs
 * Added tag to http://www.gardenroots.co.uk/content.php?18-Japanese-knotweed-biological-control-Aphalara-itadori
 * Added archive https://web.archive.org/web/20140307013849/http://www.rics.org:80/uk/knowledge/news-insight/press-releases/rics-targets-the-root-of-japanese-knotweed-risk-to-property/ to http://www.rics.org/uk/knowledge/news-insight/press-releases/rics-targets-the-root-of-japanese-knotweed-risk-to-property/

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 12:45, 29 December 2016 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 3 external links on Fallopia japonica. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20170525105020/http://www.forest.go.kr/kna/special/download/English_Names_for_Korean_Native_Plants.pdf to http://www.forest.go.kr/kna/special/download/English_Names_for_Korean_Native_Plants.pdf
 * Corrected formatting/usage for http://www.bsbi.org.uk/BSBIList2007.xls
 * Corrected formatting/usage for http://www.rics.org/uk/knowledge/news-insight/press-releases/rics-targets-the-root-of-japanese-knotweed-risk-to-property/

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 00:04, 28 September 2017 (UTC)

source
BBC Spicemix (talk) 16:31, 25 April 2018 (UTC)

Rarest?
Rarest? Student Naylor (talk) 07:33, 29 May 2022 (UTC)

Q Student Naylor (talk) 07:33, 29 May 2022 (UTC)

cardboard
cardboard fulfills a similar role as concrete slabs for mechanical removal — used over time it also has the advantage of being biodegradable. Ycleptkyara (talk) 00:40, 15 January 2023 (UTC)

Broken ref
39 reference link sends to main page of website due to broken url 86.1.166.165 (talk) 23:16, 18 May 2023 (UTC)

Thomas Hogg
The story of its introduction by Thomas Hogg should be added to this article. It's an important detail, a cautionary tale for our globalized world. Sorry, I don't have the time to do it. 2A01:CB14:2D:9600:2D7E:9E3D:18DF:E09D (talk) 08:38, 20 June 2023 (UTC)