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.



Acer ginnala
Amur maple (P) Tree  N/A PA DCNR; NRCS  Go Botany
Acer platanoides Norway maple Tree  N/A CIPWG; PA DCNR  Go Botany  NRCS-2
Acer pseudoplatanus Sycamore maple (P) Tree  Yes PA DCNR;  Go Botany
Aegopodium podagraria Goutweed/Bishops Weed  Herbaceous  Yes  Go Botany NRCS-1
Ailanthus altissima Tree of heaven  Tree  Yes  PA DCNR;  Go Botany NRCS-1 
Alliaria petiolata Garlic mustard  Herbaceous  Yes Maine; PA DCNR; TNC; UNH  Go Botany  NRCS-2
Amorpha fruticosa False indigo (P)  Shrub Yes  NRCS  Go Botany
Ampelopsis brevipedunculata Porcelainberry  Woody Vine N/A Maine; PA DCNR;  Go Botany  NRCS-2
Artemisia vulgaris Mugwort Herbaceous N/A CWMA  Go Botany NRCS-2 
Arthraxon hispidus Hairy jointgrass (P)  Grass or Grass-like  Yes PA DCNR  Go Botany
Bassia scoparia Common kochia (P) Herbaceous  Yes NRCS  Go Botany
Berberis thunbergii Japanese barberry  Shrub  N/A DEEP; Maine; PA DCNR;

Mich State  Go Botany NRCS-1;  NRCS-2
Berberis vulgaris Common barberry  Shrub Yes  NRCS; PA DCNR  Go Botany
Bromus tectorum Drooping brome-grass (P)  Grass or Grass-like Yes NRCS; PA DCNR  Go Botany
Butomus umbellatus Flowering rush (P)  Aquatic & Wetland Yes CAES; MIPN; Montana;  Go Botany
Cabomba caroliniana Fanwort  Aquatic & Wetland Yes CAES; Maine; PA DCNR; RI DEM  Go Botany
Callitriche stagnalis Pond water-starwort (P)  Aquatic & Wetland Yes CAES  Go Botany
Cardamine impatiens Narrowleaf bittercress  Herbaceous  Yes PA DCNR  Go Botany NRCS-2
Carex kobomugi Japanese sedge (P) Grass or Grass-like  Yes  Go Botany  NRCS-2
Celastrus orbiculatus Oriental bittersweet  Woody Vine Yes Maine; NRCSPA DCNR

Mich State  Go Botany NRCS-1
Centaurea stoebe Spotted knapweed  Herbaceous  Yes NRCS; PA DCNR;  Go Botany NRCS-1
Cirsium arvense Canada thistle (P)  Herbaceous  Yes PA DCNR;  Go Botany NRCS-2
Cynanchum louiseae Black swallow-wort  Herbaceous  Yes Maine; PA DCNR;  Go Botany NRCS-1
Cynanchum rossicum Pale swallow-wort  Herbaceous  Yes  PA DCNR; USFS  Go Botany NRCS-1
Datura stramonium Jimsonweed (P)  Herbaceous  Yes  PA DCNR  Go Botany
Egeria densa Brazilian water-weed (P)  Aquatic & Wetland  Yes CAES; Maine; PA DCNR; RI DEM Photos  Go Botany NRCS-1
Eichhornia crassipes Common water-hyacinth (P)  Aquatic & Wetland N/A CAES; RI DEM; UF  Go Botany NRCS-2
Elaeagnus angustifolia Russian olive (P)  Shrub Yes Maine; PA DCNR;  Go Botany NRCS-1NRCS-2
Elaeagnus umbellata Autumn olive  Shrub Yes CIPWG; DEEP; Maine; NRCS; PA DCNR 

Mich State  Go Botany NRCS-1NRCS-2
Elsholtzia ciliata Crested late-summer mint (P)  Herbaceous Yes IPANE  Go Botany
Euonymus alatus Winged euonymus  Shrub N/A CIPWG; NRCS; PA DCNR  Go Botany NRCS-1
Euphorbia cyparissias Cypress spurge (P)  Herbaceous Yes IPANE;  Go Botany NRCS-1
Euphorbia esula Leafy spurge  Herbaceous  Yes  NRCS;  Go Botany
Frangula alnus Glossy Buckthorn  Shrub  N/A DEEP; Maine; NRCS; PA DCNR;

Mich State  Go Botany NRCS-1
Froelichia gracilis Slender snake cotton  Herbaceous  Yes IPANE  Go Botany
Glechoma hederacea Ground ivy (P)  Herbaceous Yes  NRCS  Go Botany
Glyceria maxima Reed mannagrass (P)  Grass or Grass-like Yes  IPANE  Go Botany
Heracleum mantegazzianum Giant hogweed (P)  Herbaceous Yes  CIPWG; PA DCNR; Photos  Go Botany
Hesperis matronalis Dame’s rocket  Herbaceous  Yes  PA DCNR;  Go Botany  NRCS-1 
Humulus japonicus Japanese hops (P)  Herbaceous Yes  PA DCNR;  Go Botany NRCS-2
Hydrilla verticillata Hydrilla  Aquatic & Wetland  Yes CAES; Maine; NRCS Photos  Go Botany  NRCS-2
Impatiens glandulifera Ornamental jewelweed (P)  Herbaceous Yes IPANE; WA NWCB  Go Botany NRCS-2
Iris pseudacorus Yellow iris  Aquatic & Wetland Yes CAES; CIPWG; NRCS; PA DCNR  Go Botany  NRCS-2
Lepidium latifolium Perennial pepperweed  Herbaceous Yes PCA; WA NWCB  Go Botany
Ligustrum obtusifolium Border privet (P)  Shrub Yes PA DCNR;  Go Botany NRCS-2
Ligustrum ovalifolium California privet (P)  Shrub  N/A  Go Botany NRCS-2
Ligustrum vulgare European privet (P)  Shrub  N/A PA DCNR;  Go Botany  NRCS-2
Lonicera japonica Japanese honeysuckle  Woody Vine Yes DEEP; Maine; PA DCNR; USFS  Go Botany NRCS-1NRCS-2
Lonicera maackii Amur honeysuckle  Shrub Yes PA DCNR; PCA; TNC; USFS  Go Botany  NRCS-2
Lonicera morrowii Morrow’s honeysuckle  Shrub Yes Maine; NRCS; PA DCNR; TNC; USFS  Go Botany NRCS-2
Lonicera tatarica Tatarian honeysuckle (P)  Shrub Yes Maine; NRCS; PA DCNR; TNC;  Go Botany  NRCS-2
Lonicera x bella Belle honeysuckle  Shrub Yes Maine; PA DCNR; TNC; Wisconsin NRCS-2
Lonicera xylosteum Dwarf honeysuckle (P)  Shrub Yes TNC  Go Botany NRCS-2
Lychnis flos-cuculi Ragged robin (P)  Herbaceous Yes  IPANE  Go Botany
Lysimachia nummularia Moneywort (P)  Herbaceous  N/A  PA DCNR; USFS  Go Botany
Lysimachia vulgaris Garden loosestrife (P)  Herbaceous Yes IPANE; UC-Davis; WA NWCB  Go Botany
Lythrum salicaria Purple loosestrife  Aquatic & Wetland  Yes  CAES; Maine; NRCS; PA DCNR;  TNC; UConn  Go Botany  NRCS-1;  NRCS-2
Marsilea quadrifolia European waterclover (P)  Aquatic & Wetland  Yes CAES; IPANE  Go Botany
Microstegium vimineum Japanese stilt grass  Grass or Grass-like  Yes Maine; PA DCNR; TNC;  Go Botany NRCS-1NRCS-2 
Miscanthus sinensis Eulalia (P)  Grass or Grass-like N/A IPANE; PA DCNR; USFS  Go Botany
Myosotis scorpioides Forget-me-not  Aquatic & Wetland  Yes CAES; IPANE  Go Botany NRCS-2
Myriophyllum aquaticum Parrotfeather (P)  Aquatic & Wetland  Yes CAES; PA DCNR; RI DEM; WA NWCB  Go Botany NRCS-1NRCS-2
Myriophyllum heterophyllum Variable-leaf watermilfoil  Aquatic & Wetland Yes CAES;  RI DEM; WA NWCB  Go Botany NRCS-1
Myriophyllum spicatum Eurasian watermilfoil  Aquatic & Wetland Yes CAES; Maine; NRCS; PA DCNR;  RI DEM; WA NWCB  Go Botany  NRCS-1
Najas minor Brittle water-nymph (P)  Aquatic & Wetland Yes  CAES; IPANE; RI DEM  Go Botany
Nasturtium microphyllum Onerow yellowcress (P)  Aquatic & Wetland Yes CAES; IPANE  Go Botany
Nasturtium officinale Watercress (P)  Aquatic & Wetland Yes CAES; WA NWCB  Go Botany
Nelumbo lutea American water lotus (P)  Aquatic & Wetland Yes CAES; RI DEM  Go Botany  NRCS-2
Nymphoides peltata Yellow floating heart (P)  Aquatic & Wetland Yes CAES; IPANE; RI DEM; WA NWCB  Go Botany
Onopordum acanthium Scotch thistle (P)  Herbaceous  Yes IPANE; WA NWCB  Go Botany
Ornithogalum umbellatum Star-of-Bethlehem (P)  Herbaceous N/A IPANE; PA DCNR;  Go Botany
Paulownia tomentosa Princess tree (P)  Tree Yes  PA DCNR;  Go Botany
Phalaris arundinacea Reed canary grass  Grass or Grass-like N/A NRCS; PA DCNR; WA NWCB  Go Botany NRCS-2
Phragmites australis Common reed  Grass or Grass-like  Yes Maine; NRCS;  PA DCNR; TNC;  WA NWCB  Go Botany  NRCS-1NRCS-2
Pistia stratiotes Water lettuce (P)  Aquatic & Wetland  N/A  CAES; IPANE
Poa compressa Canada bluegrass (P)  Grass or Grass-like  Yes IPANE; NRCS  Go Botany
Polygonum caespitosum Bristled knotweed  Herbaceous  Yes IPANE
Polygonum cuspidatum Japanese knotweed  Herbaceous Yes DEEPMaine; MI DNRNRCS; PA DCNR; PCA; TNC

Mich State NRCS-2
Polygonum perfoliatum Mile-a-minute vine  Herbaceous Yes CIPWG; Maine; NRCS; UConn; Photos  Go Botany NRCS-1;  NRCS-2
Polygonum sachalinense Giant knotweed (P)  Herbaceous Yes PA DCNR; WA NWCB  Go Botany
Populus alba White poplar (P)  Tree Yes IPANE;  Go Botany
Potamogeton crispus Curly-leafed pondweed  Aquatic & Wetland Yes CAES; NRCS; PA DCNR; RI DEM; WA NWCB  Go Botany  NRCS-1
Pueraria montana Kudzu (P)  Woody Vine Yes PA DCNR;  USFS; WA NWCB Photos  Go Botany NRCS-2
Ranunculus ficaria Fig buttercup  Herbaceous Yes  PCA NRCS-2
Rhamnus cathartica Common buckthorn  Shrub  Yes Maine; NRCS; PA DCNR;  Go Botany  NRCS-1
Robinia pseudoacacia Black locust  Tree  N/A NRCS;  Go Botany NRCS-1
Rosa multiflora Multiflora rose  Shrub  Yes DEEP; Maine; NRCS; PA DCNR; TNC  Go Botany NRCS-1NRCS-2
Rosa rugosa Rugosa rose (P)  Shrub N/A  NRCS  Go Botany
Rubus phoenicolasius Wineberry  Shrub  Yes PA DCNR; USFS  Go Botany
Rumex acetosella Sheep sorrel (P)  Herbaceous  Yes  USFS  Go Botany
Salvinia molesta Giant salvinia (P)  Aquatic & Wetland  Yes CAES; IPANE;  Go Botany
Senecio jacobaea Tansy ragwort (P)  Herbaceous Yes IPANE; WA NWCB  Go Botany
Silphium perfoliatum Cup plant (P)  Herbaceous Yes  NRCS  Go Botany
Solanum dulcamara Bittersweet nightshade (P)  Herbaceous Yes  IPANE; USFS  Go Botany
Trapa natans Water chestnut  Aquatic & Wetland Yes CAES; Maine; PA DCNR; PCA; RI DEM  Go Botany  NRCS-1; NRCS-2
Tussilago farfara Coltsfoot  Herbaceous Yes  IPANE; USFS; WA NWCB  Go Botany
Valeriana officinalis Garden heliotrope (P)  Herbaceous Yes IPANE;  Go Botany




*CAES= Connecticut Agricultural Experiment Station CIPWG= Connecticut Invasive Plant Working Group DEEP= Connecticut Department of Energy and Environmental Protection 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 Conservatioice, United States Department of Agriculture PCA= Plant Conservation Alliance, National Park Service PA DCNR= Pennsylvania Department of Conservation and Natural Resources RI DEM= RIsland Department of Environmental Management TNC= The Nature Conservancy UC-Davis= University of California-Davis, Cooperative Extension & Agricultural Experiment Station  USFS= US Forest Service, United States Department of Agriculture UF= University of Fla Extension UNH= University of New Hampshire Extension WA NWCB= Washington State Noxious Weed Control Board