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Japanese Knotweed

Reynoutria japonica

—
Not native

Not native to Florida. How scores work Is it native here?

Profile 65%

Height
10–13 feet
Spread
3–20 feet
Light
Full sun
Soil moisture
Usually moist

At a glance

Life cycle
Perennial

Not yet recorded · Leaves · Bloom

This plant is missing most of its facts, so Quercus is looking them up in old botany books.

Recorded in 1 Florida county.

Ecological relationships

Who uses this plant?

What these records mean

43CaterpillarsGenus host records with ranges including FL

Genus host records with ranges including FL · Polygonum

  • Achyra rantalisGarden Webworm Moth
  • Acronicta insularisHenry's Marsh Moth, Cattail Caterpillar
  • Acronicta oblinitaSmeared Dagger
  • Anticlea multiferataMany-Lined Carpet
  • Apantesis argeArge Tiger Moth
  • Apantesis naisNais Tiger Moth
  • Archips semiferanusOak Leafroller Moth
  • Calothysanis amaturariaCross-Lined Wave
  • Chionodes discoocellellaEyeringed Chionodes
  • Costaconvexa centrostrigariaBent-Lined Carpet
Show all 43
  • Dypterygia rozmaniAmerican Bird's-Wing
  • Elophila icciusalisPondside Pyralid, Pondside Crambid
  • Elophila obliteralisWaterlily Leafcutter Moth
  • Emmelina monodactylaMorning-Glory Plume Moth
  • Epiblema otiosanaBidens Borer Moth
  • Eusarca confusariaConfused Eusarca
  • Feltia subterraneaSubterranean Dart, Granulate Cutworm
  • Haematopis gratariaChickweed Geometer
  • Helicoverpa zeaCorn Earworm Moth
  • Homophoberia apicosaBlack Wedge-Spot, Smartweed Groundling
  • Hyles lineataWhite-Lined Sphinx
  • Hypena scabraGreen Cloverworm Bomolocha, Black Snout
  • Maliattha synochitisBlack-Dotted Lithacodia, Black-Dotted Glyph, Brass-Dotted Grass Moth
  • Melanolophia canadariaCanadian Melanolphia, Variable Redmarked Looper
  • Metarranthis duariaRuddy Metarranthis
  • Nomophila nearcticaLucerne Moth, American Celery Webworm
  • Orthonama obstipataThe Gem
  • Ostrinia obumbratalisSmartweed Borer
  • Ostrinia penitalisAmerican Lotus Borer, Lily Moth
  • Parapoynx obscuralisObscure Pondweed Moth
  • Patania silicalisHerbivorous Patania, Herbivorous Pleuroptya
  • Prochoerodes lineolaLarge Maple Spanworm Moth
  • Pseudeustrotia carneolaPink-Barred Lithacodia, Pink-Barred Pseudeustrotia
  • Saucrobotys futilalisDogbane Saucrobotys
  • Schinia scissoidesDivided Flower Moth
  • Schinia spinosaeSpinose Flower Moth
  • Scopula limboundataLarge Lace-Border
  • Spilosoma congruaAgreeable Tiger Moth
  • Spilosoma virginicaVirginian Tiger Moth, Yellow Woolybear Moth, Yellow Bear
  • Strymon melinusGray Hairstreak
  • Xanthotype sospetaCrocus Geometer
  • Aroga alleriella
  • Schinia subspinosae
Shropshire & Tallamy 2025, Lepidoptera of North America north of Mexico, ZooKeys 1261 (ODbL)
—BeesSoutheastern regional records
—Specialist beesPollen specialists
58BirdsRecorded genus food-resource interactions; not a state feeding claim

Recorded genus food-resource interactions; not a state feeding claim · Polygonum

  • Agelaius phoeniceusRed-winged Blackbird
  • Aix sponsaWood Duck
  • Alectoris chukarChukar
  • Anas acutaNorthern Pintail
  • Anas creccaGreen-winged Teal
  • Anas platyrhynchosMallard
  • Anser albifronsGreater White-fronted Goose
  • Anthus rubescensAmerican Pipit
  • Aythya affinisLesser Scaup
  • Aythya americanaRedhead
Show all 58
  • Aythya collarisRing-necked Duck
  • Aythya valisineriaCanvasback
  • Bonasa umbellusRuffed Grouse
  • Bucephala clangulaCommon Goldeneye
  • Callipepla californicaCalifornia Quail
  • Centrocercus urophasianusGreater Sage-Grouse
  • Colinus virginianusNorthern Bobwhite
  • Columba liviaRock Pigeon
  • Columbina passerinaCommon Ground Dove
  • Coturnicops noveboracensisYellow Rail
  • Dendragapus obscurusDusky Grouse
  • Dendrocygna autumnalisBlack-bellied Whistling-Duck
  • Dolichonyx oryzivorusBobolink
  • Eremophila alpestrisHorned Lark
  • Euphagus cyanocephalusBrewer's Blackbird
  • Francolinus francolinusBlack Francolin
  • Fulica americanaAmerican Coot
  • Gallinula galeataCommon Gallinule
  • Haemorhous mexicanusHouse Finch
  • Junco hyemalisDark-eyed Junco
  • Lagopus lagopusWillow Ptarmigan
  • Mareca americanaAmerican Wigeon
  • Meleagris gallopavoWild Turkey
  • Melospiza melodiaSong Sparrow
  • Melozone crissalisCalifornia Towhee
  • Molothrus aterBrown-headed Cowbird
  • Oreortyx pictusMountain Quail
  • Oxyura jamaicensisRuddy Duck
  • Passer domesticusHouse Sparrow
  • Perdix perdixGray Partridge
  • Pheucticus melanocephalusBlack-headed Grosbeak
  • Pinicola enucleatorPine Grosbeak
  • Pipilo maculatusSpotted Towhee
  • Porzana carolinaSora
  • Quiscalus quisculaCommon Grackle
  • Rallus elegansKing Rail
  • Rallus limicolaVirginia Rail
  • Sialia mexicanaWestern Bluebird
  • Sialia sialisEastern Bluebird
  • Spinus psaltriaLesser Goldfinch
  • Spizella passerinaChipping Sparrow
  • Sturnus vulgarisEuropean Starling
  • Turdus migratoriusAmerican Robin
  • Tympanuchus phasianellusSharp-tailed Grouse
  • Vireo griseusWhite-eyed Vireo
  • Zenaida macrouraMourning Dove
  • Zonotrichia atricapillaGolden-crowned Sparrow
  • Zonotrichia leucophrysWhite-crowned Sparrow
Hurlbert, Olsen, Sawyer & Winner 2021, Avian Diet Database, Scientific Data 8: 260 (CC0)

Direct food only: birds recorded eating this genus across North America. Caterpillars on host plants also feed nesting birds. NC Native Plant Society: butterfly gardening

Growing and identification

Plant details

Family
Polygonaceae
Flower color
Cream, green or white

What its natural habitat tells you

Safety has not been reviewed for this plant; check toxicity and thorns before planting.

Growing sources and scope
Also known as

Polygonum cuspidatum; knotweed

Conservation status

Florida rankSNA
Global rankGNR
FL statusNot verified
Federal statusNot verified

Conservation source Global and federal source

Native alternatives

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Sources