Persicaria decipiens(R.Br.) K.L.Wilson

knotweed

WFO wfo-0000488020 Accepted WFO 2026-06 8 photographs CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Persicaria decipiens, photographed by Tony Rebelo
fig. a Tony Rebelo, CC BY-SA 4.0 / 2022-06-11 / obs. 205880216

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.

Native range 88 botanical countries

Regions where Persicaria decipiens is native: Algeria, Angola, Benin, Botswana, Burkina, Burundi, Cameroon, Canary Is., Cape Provinces, Cape Verde, Caprivi Strip, Central African Republic, Chad, Congo, DR Congo, Egypt, Ethiopia, Free State, Gabon, Gambia, Ghana, Guinea, Gulf of Guinea Is., Ivory Coast, Kenya, KwaZulu-Natal, Lesotho, Liberia, Libya, Madeira, Malawi, Mali, Morocco, Mozambique, Namibia, Niger, Nigeria, Northern Provinces, Rwanda, Senegal, Sierra Leone, Somalia, Sudan-South Sudan, Tanzania, Togo, Tunisia, Uganda, Zambia, Zimbabwe, China Southeast, Cyprus, East Aegean Is., Iran, Iraq, Lebanon-Syria, Palestine, Türkiye, Yemen, Assam, Bangladesh, India, Myanmar, New Guinea, Sri Lanka, Chatham Is., New South Wales, New Zealand North, New Zealand South, Norfolk Is., Northern Territory, Queensland, South Australia, Tasmania, Victoria, Western Australia, Albania, Baleares, Bulgaria, Corse, France, Greece, Italy, Kriti, Portugal, Sardegna, Sicilia, Spain, Türkiye-in-Europe AlgeriaAngolaBeninBotswanaBurkinaBurundiCameroonCape ProvincesCaprivi StripCentral African RepublicChadCongoDR CongoEgyptEthiopiaFree StateGabonGambiaGhanaGuineaGulf of Guinea Is.Ivory CoastKenyaKwaZulu-NatalLesothoLiberiaLibyaMalawiMaliMoroccoMozambiqueNamibiaNigerNigeriaNorthern ProvincesRwandaSenegalSierra LeoneSomaliaSudan-South SudanTanzaniaTogoTunisiaUgandaZambiaZimbabweChina SoutheastCyprusEast Aegean Is.IranIraqLebanon-SyriaPalestineTürkiyeYemenAssamBangladeshIndiaMyanmarNew GuineaSri LankaNew South WalesNew Zealand NorthNew Zealand SouthNorthern TerritoryQueenslandSouth AustraliaTasmaniaVictoriaWestern AustraliaAlbaniaBulgariaCorseFranceGreeceItalyKritiPortugalSiciliaSpainTürkiye-in-Europe Canary Is.Cape VerdeMadeiraChatham Is.Norfolk Is.BalearesSardegna
Native distribution of Persicaria decipiens, 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
Algeria ALG AFRICA
Angola ANG
Benin BEN
Botswana BOT
Burkina BKN
Burundi BUR
Cameroon CMN
Canary Is. CNY
Cape Provinces CPP
Cape Verde CVI
Caprivi Strip CPV
Central African Republic CAF
Chad CHA
Congo CON
DR Congo ZAI
Egypt EGY
Ethiopia ETH
Free State OFS
Gabon GAB
Gambia GAM
Ghana GHA
Guinea GUI
Gulf of Guinea Is. GGI
Ivory Coast IVO
Kenya KEN
KwaZulu-Natal NAT
Lesotho LES
Liberia LBR
Libya LBY
Madeira MDR
Malawi MLW
Mali MLI
Morocco MOR
Mozambique MOZ
Namibia NAM
Niger NGR
Nigeria NGA
Northern Provinces TVL
Rwanda RWA
Senegal SEN
Sierra Leone SIE
Somalia SOM
Sudan-South Sudan SUD
Tanzania TAN
Togo TOG
Tunisia TUN
Uganda UGA
Zambia ZAM
Zimbabwe ZIM
Albania ALB EUROPE
Baleares BAL
Bulgaria BUL
Corse COR
France FRA
Greece GRC
Italy ITA
Kriti KRI
Portugal POR
Sardegna SAR
Sicilia SIC
Spain SPA
Türkiye-in-Europe TUE
Chatham Is. CTM AUSTRALASIA
New South Wales NSW
New Zealand North NZN
New Zealand South NZS
Norfolk Is. NFK
Northern Territory NTA
Queensland QLD
South Australia SOA
Tasmania TAS
Victoria VIC
Western Australia WAU
China Southeast CHS ASIA-TEMPERATE
Cyprus CYP
East Aegean Is. EAI
Iran IRN
Iraq IRQ
Lebanon-Syria LBS
Palestine PAL
Türkiye TUR
Yemen YEM
Assam ASS ASIA-TROPICAL
Bangladesh BAN
India IND
Myanmar MYA
New Guinea NWG
Sri Lanka SRL

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 285 in flower of 334 examined

Proportion of examined Persicaria decipiens in flower, by month
Month In flower Examined Share 95% interval
Jan 39 45 87% 74% to 94%
Feb 37 46 80% 67% to 89%
Mar 41 46 89% 77% to 95%
Apr 59 65 91% 81% to 96%
May 28 34 82% 66% to 92%
Jun 17 21 81% 60% to 92%
Jul 9 11 82% 52% to 95%
Aug 2 3 too few examined
Sep 4 4 too few examined
Oct 8 11 73% 43% to 90%
Nov 21 23 91% 73% to 98%
Dec 20 25 80% 61% to 91%

Peak flowering in Nov. Each bar is the share of Persicaria decipiens 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. 285 of 334 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 2 months have fewer than 5 examined observations, so no proportion is drawn for them. 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.

Also published as 8 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.

  • Persicaria minor subsp. decipiens (R.Br.) Soják
  • Persicaria salicifolia (Brouss. ex Willd.) Assenov
  • Persicaria serrulata (Lag.) Webb & Moq.
  • Polygonum decipiens R.Br.
  • Polygonum salicifolium Brouss. ex Willd.
  • Polygonum scabrum var. glabrescens Feinbrun
  • Polygonum serrulatoides H.Lindb.
  • Polygonum serrulatum Lag.

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 POSA23. 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.