Invasive Plant List

Click below to view the Connecticut Invasive Plant List. The list includes Invasive and Potentially Invasive Plants as determined by the Connecticut Invasive Plants Council in accordance with Connecticut General Statutes §22a-381a through §22a-381d. The list was most recently re-printed in October 2018.

2018 Re-Printed CT Invasive Plant List sorted by scientific name (PDF)  

(P) indicates Potentially Invasive (all others are considered Invasive in Connecticut)

“Prohibited by Statute?” column indicates prohibited status: Yes=prohibited from importation, movement, sale, purchase, transplanting, cultivation and distribution under CT General Statutes §22a-381d; N/A=not prohibited

Additional control information on these plants and other invasive plants is available here.

SPECIES

(SCIENTIFIC NAME)

SPECIES(COMMON NAME) GROWTH FORM OR HABIT PROHIBITED BY STATUTE? FACTSHEETS* PHOTOS GO BOTANY LINK ID SHEETS
Acer ginnala
Amur maple (P) Tree  N/A PA DCNR

USDA

 Invasive.org  Go Botany
Acer platanoides Norway maple Tree  N/A UMD  Invasive.org  Go Botany  NRCS-2
Acer pseudoplatanus Sycamore maple (P) Tree  Yes Morton Arb

MSU

 Invasive.org  Go Botany
Aegopodium podagraria Goutweed/Bishops Weed  Herbaceous  Yes Invasive.org

FS

 Invasive.org  Go Botany NRCS-1
Ailanthus altissima Tree of heaven  Tree  Yes UConn IPM

PSU Ext

FS

 Invasive.org  Go Botany NRCS-1 
Alliaria petiolata Garlic mustard  Herbaceous  Yes UConn IPM Maine

TNC

UNH

MSU

 Invasive.org  Go Botany  NRCS-2
Amorpha fruticosa False indigo (P)  Shrub Yes  

Invasive Plant  Atlas

USDA

 Invasive.org  Go Botany
Ampelopsis brevipedunculata Porcelainberry  Woody Vine N/A  Invasive.org  Go Botany  NRCS-2
Artemisia vulgaris Mugwort Herbaceous N/A UConn/CIPWG

UConn IPM

NYIS

 Invasive.org  Go Botany NRCS-2 
Arthraxon hispidus Hairy jointgrass (P)  Grass or Grass-like  Yes Invasive.org  Invasive.org  Go Botany
Bassia scoparia Common kochia (P) Herbaceous  Yes USDA  Invasive.org  Go Botany
Berberis thunbergii Japanese barberry  Shrub  N/A UConn IPM DEEP Maine

PA DCNR

Mich State

 Invasive.org  Go Botany NRCS-1;  NRCS-2
Berberis vulgaris Common barberry  Shrub Yes MDA State

UMN EXT

 Invasive.org  Go Botany
Bromus tectorum Drooping brome-grass (P)  Grass or Grass-like Yes NRCS

PA DCNR

 Invasive.org  Go Botany
Butomus umbellatus Flowering rush (P)  Aquatic & Wetland Yes CAES

NRCS

Montana

Invasive Plant Atlas

 Invasive.org  Go Botany
Cabomba caroliniana Fanwort  Aquatic & Wetland Yes CAES

Maine

PA DCNR

 Invasive.org  Go Botany
Callitriche stagnalis Pond water-starwort (P)  Aquatic & Wetland Yes CAES

MSU

 Invasive.org  Go Botany
Cardamine impatiens Narrowleaf bittercress  Herbaceous  Yes PA DCNR

UMN EXT

 Invasive.org  Go Botany NRCS-2
Carex kobomugi Japanese sedge (P) Grass or Grass-like  Yes PCA  Invasive.org  Go Botany  NRCS-2
Celastrus orbiculatus Asiatic bittersweet  Woody Vine Yes  UConn IPM PSU

Mich State

NRCS

 Invasive.org  Go Botany NRCS-1
Centaurea stoebe Spotted knapweed  Herbaceous  Yes USDA

PA DCNR

 Invasive.org  Go Botany NRCS-1
Cirsium arvense Canada thistle (P)  Herbaceous  Yes PA DCNR  Invasive.org  Go Botany NRCS-2
Cynanchum louiseae Black swallow-wort  Herbaceous  Yes UConn IPM

UMN

PA DCNR

Invasive.org  Go Botany NRCS-1
Cynanchum rossicum Pale swallow-wort  Herbaceous  Yes UConn IPM

PA DCNR

USFS

FS flyer

Invasive.org  Go Botany NRCS-1
Datura stramonium Jimsonweed (P)  Herbaceous  Yes USU EXT Invasive.org  Go Botany
Egeria densa Brazilian water-weed (P)  Aquatic & Wetland  Yes CAES

Maine

PA DCNR

RI DEM

Invasive.org Photos  Go Botany NRCS-1
Eichhornia crassipes Common water-hyacinth (P)  Aquatic & Wetland N/A CAES

RI DEM

UF

Invasive.org  Go Botany NRCS-2
Elaeagnus angustifolia Russian olive (P)  Shrub Yes Maine

PA DCNR

Invasive.org  Go Botany NRCS-1

NRCS-2

Elaeagnus umbellata Autumn olive  Shrub Yes CIPWG

Maine

PA DCNR

Mich State

WVU EXT

Invasive.org  Go Botany NRCS-1

NRCS-2

Elsholtzia ciliata Crested late-summer mint (P)  Herbaceous Yes IPANE Invasive.org  Go Botany
Euonymus alatus Winged euonymus  Shrub N/A UConn IPM

NRCS

PA DCNR

Invasive.org  Go Botany NRCS-1
Euphorbia cyparissias Cypress spurge (P)  Herbaceous Yes IPANE Invasive.org  Go Botany NRCS-1
Euphorbia esula Leafy spurge  Herbaceous  Yes USDA Invasive.org  Go Botany
Frangula alnus Glossy Buckthorn  Shrub  N/A DEEP

Maine

NRCS

PA DCNR

Mich State

 Invasive.org  Go Botany NRCS-1
Froelichia gracilis Slender snake cotton  Herbaceous  Yes IPANE  Invasive.org  Go Botany
Glechoma hederacea Ground ivy (P)  Herbaceous Yes  USDA  Invasive.org  Go Botany
Glyceria maxima Reed mannagrass (P)  Grass or Grass-like Yes  USGS

EDD Maps

 Invasive.org  Go Botany
Heracleum mantegazzianum Giant hogweed (P)  Herbaceous Yes  CIPWG

PA DCNR

Invasive.org Photos  Go Botany
Hesperis matronalis Dame’s rocket  Herbaceous  Yes OSU Invasive.org  Go Botany  NRCS-1 
Humulus japonicus Japanese hops (P)  Herbaceous Yes  PA DCNR Invasive.org  Go Botany NRCS-2
Hydrilla verticillata Hydrilla  Aquatic & Wetland  Yes CAES

Maine

NRCS

Invasive.org Photos  Go Botany  NRCS-2
Impatiens glandulifera Ornamental jewelweed (P)  Herbaceous Yes EDD Maps

WA NWCB

USGS

Invasive.org  Go Botany NRCS-2
Iris pseudacorus Yellow iris  Aquatic & Wetland Yes CAES

CIPWG

USDA

PA DCNR

Invasive.org  Go Botany  NRCS-2
Lepidium latifolium Perennial pepperweed  Herbaceous Yes EDD Maps

WA NWCB

USFS

 Invasive.org  Go Botany
Ligustrum obtusifolium Border privet (P)  Shrub Yes PA DCNR  Invasive.org  Go Botany NRCS-2
Ligustrum ovalifolium California privet (P)  Shrub  N/A EDD Maps  Invasive.org NRCS-2
Ligustrum vulgare European privet (P)  Shrub  N/A PA DCNR  Invasive.org  Go Botany  NRCS-2
Lonicera japonica Japanese honeysuckle  Woody Vine Yes DEEP

Maine

PA DCNR

USFS

 Invasive.org  Go Botany NRCS-1

NRCS-2

Lonicera maackii Amur honeysuckle  Shrub Yes PA DCNR

TNC

USFS

 Invasive.org  Go Botany  NRCS-2
Lonicera morrowii Morrow’s honeysuckle  Shrub Yes Maine

NRCS

PA DCNR

TNC

 Invasive.org  Go Botany NRCS-2
Lonicera tatarica Tatarian honeysuckle (P)  Shrub Yes Maine

NRCS

PA DCNR

TNC

Invasive.org  Go Botany  NRCS-2
Lonicera x bella Belle honeysuckle  Shrub Yes Maine

PA DCNR

TNC

Wisconsin

Invasive.org NRCS-2
Lonicera xylosteum Dwarf honeysuckle (P)  Shrub Yes TNC Invasive.org  Go Botany NRCS-2
Lychnis flos-cuculi Ragged robin (P)  Herbaceous Yes  IPANE Invasive.org  Go Botany
Lysimachia nummularia Moneywort (P)  Herbaceous  N/A  PA DCNR

USFS

Invasive.org  Go Botany
Lysimachia vulgaris Garden loosestrife (P)  Herbaceous Yes IPANE

UC-Davis

WA NWCB

 Invasive.org  Go Botany
Lythrum salicaria Purple loosestrife  Aquatic & Wetland  Yes  UConn

CAES

Maine

NRCS

PA DCNR

TNC

 Invasive.org  Go Botany  NRCS-1

NRCS-2

Marsilea quadrifolia European waterclover (P)  Aquatic & Wetland  Yes CAES

IPANE

 Invasive.org  Go Botany
Microstegium vimineum Japanese stiltgrass  Grass or Grass-like  Yes UConn IPM

Maine

PA DCNR

TNC

 Invasive.org  Go Botany NRCS-1

NRCS-2 

Miscanthus sinensis Eulalia (P)  Grass or Grass-like N/A IPANE

PA DCNR

USFS

 Invasive.org  Go Botany
Myosotis scorpioides Forget-me-not  Aquatic & Wetland  Yes CAES

IPANE

 Invasive.org  Go Botany NRCS-2
Myriophyllum aquaticum Parrotfeather (P)  Aquatic & Wetland  Yes CAES

PA DCNR

RI DEM

WA NWCB

Invasive.org  Go Botany NRCS-1

NRCS-2

Myriophyllum heterophyllum Variable-leaf watermilfoil  Aquatic & Wetland Yes CAES

RI DEM

WA NWCB

Invasive.org  Go Botany NRCS-1
Myriophyllum spicatum Eurasian watermilfoil  Aquatic & Wetland Yes CAES

Maine

USDA

PA DCNR

WA NWCB

Invasive.org  Go Botany  NRCS-1
Najas minor Brittle water-nymph (P)  Aquatic & Wetland Yes  CAES

IPANE

Invasive.org  Go Botany
Nasturtium microphyllum Onerow yellowcress (P)  Aquatic & Wetland Yes CAES

MSU

EDD Maps

Invasive.org  Go Botany
Nasturtium officinale Watercress (P)  Aquatic & Wetland Yes CAES

FWS

Invasive.org  Go Botany
Nelumbo lutea American water lotus (P)  Aquatic & Wetland Yes CAES

RI DEM

Invasive.org  Go Botany  NRCS-2
Nymphoides peltata Yellow floating heart (P)  Aquatic & Wetland Yes CAES

IPANE

RI DEM

WA NWCB

Invasive.org  Go Botany
Onopordum acanthium Scotch thistle (P)  Herbaceous  Yes IPANE

WA NWCB

 Invasive.org  Go Botany
Ornithogalum umbellatum Star-of-Bethlehem (P)  Herbaceous N/A IPANE

PA DCNR

 Invasive.org  Go Botany
Paulownia tomentosa Princess tree (P)  Tree Yes  PA DCNR

FS

 Invasive.org  Go Botany
Phalaris arundinacea Reed canary grass  Grass or Grass-like N/A DNR MN

PA DCNR

WA NWCB

 Invasive.org  Go Botany NRCS-2
Phragmites australis Common reed  Grass or Grass-like  Yes   UConn IPM PA DCNR 

TNC  

WA NWCB

 Invasive.org  Go Botany  NRCS-1

NRCS-2

Pistia stratiotes Water lettuce (P)  Aquatic & Wetland N/A CAES

IPANE

 Invasive.org
Poa compressa Canada bluegrass (P)  Grass or Grass-like  Yes IPANE

USDA

 Invasive.org  Go Botany
Polygonum caespitosum Bristled knotweed  Herbaceous  Yes  Invasive.org
Polygonum cuspidatum Japanese knotweed  Herbaceous Yes DEEP

NRCS

PA DCNR

TNC

Mich State

Invasive.org NRCS-2
Polygonum perfoliatum Mile-a-minute vine  Herbaceous Yes UConn IPM

UConn MAM

Maine

USFS

Invasive.org Photos  Go Botany NRCS-1

NRCS-2

Polygonum sachalinense Giant knotweed (P)  Herbaceous Yes PA DCNR

WA NWCB

Invasive.org  Go Botany
Populus alba White poplar (P)  Tree Yes MAINE Invasive.org  Go Botany
Potamogeton crispus Curly-leafed pondweed  Aquatic & Wetland Yes CAES

PSU EXT

PA DCNR

WA NWCB

Invasive.org  Go Botany  NRCS-1
Pueraria montana Kudzu (P)  Woody Vine Yes PA DCNR

USFS

WA NWCB

Invasive.org Photos  Go Botany NRCS-2
Ranunculus ficaria Fig buttercup  Herbaceous Yes  PCA  Invasive.org NRCS-2
Rhamnus cathartica Common buckthorn  Shrub  Yes Maine

NRCS

PA DCNR

Invasive.org  Go Botany NRCS-1
Robinia pseudoacacia Black locust  Tree  N/A NRCS Invasive.org  Go Botany NRCS-1
Rosa multiflora Multiflora rose  Shrub  Yes UConn IPM DEEP 

Maine 

NRCS 

PA DCNR  

TNC

Invasive.org  Go Botany NRCS-1

NRCS-2

Rosa rugosa Rugosa rose (P)  Shrub N/A USDA Invasive.org  Go Botany
Rubus phoenicolasius Wineberry  Shrub  Yes PA DCNR

USFS

 Invasive.org  Go Botany
Rumex acetosella Sheep sorrel (P)  Herbaceous  Yes  USFS  Invasive.org  Go Botany
Salvinia molesta Giant salvinia (P)  Aquatic & Wetland  Yes CAES

EDD Maps

CABI

 Invasive.org
Senecio jacobaea Tansy ragwort (P)  Herbaceous Yes EDD Maps

WA NWCB

EDD Maps

 Invasive.org  Go Botany
Silphium perfoliatum Cup plant (P)  Herbaceous Yes  USDA Invasive.org  Go Botany
Solanum dulcamara Bittersweet nightshade (P)  Herbaceous Yes  IPANE

USFS

 Invasive.org  Go Botany
Trapa natans Water chestnut  Aquatic & Wetland Yes CAES

Maine

PA DCNR

RI DEM

 Invasive.org  Go Botany  NRCS-1; NRCS-2
Tussilago farfara Coltsfoot  Herbaceous Yes  IPANE

USFS

WA NWCB

 Invasive.org  Go Botany
Valeriana officinalis Garden heliotrope (P)  Herbaceous Yes IPANE  Invasive.org  Go Botany

*CAES = Connecticut Agricultural Experiment Station; CIPWG = Connecticut Invasive Plant Working Group; DEEP = Connecticut Department of Energy and Environmental Protection; EDD Maps = Early Detection and Distribution Mapping System; IPANE = Invasive Plant Atlas of New England; Maine = University of Maine Cooperative Extension; MIPN = Midwest Invasive Plant Network; Montana = Montana State University Extension; NRCS = Natural Resource Conservation; PCA = Plant Conservation Alliance, National Park Service; PA DCNR = Pennsylvania Department of Conservation and Natural Resources; RI DEM = Rhode Island Department of Environmental Management; TNC = The Nature Conservancy; UC-Davis = University of California-Davis, Cooperative Extension & Agricultural Experiment Station; UConn = University of Connecticut; USFS = US Forest Service, United States Department of Agriculture; UF = University of Fla Extension; UNH = University of New Hampshire Extension; USDA = United States Department of Agriculture; WA NWCB = Washington State Noxious Weed Control Board