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.
(P) indicates Potentially Invasive (all others are considered Invasive in Connecticut)
"Prohibited by Statute" indicates prohibited status in Connecticut:
Yes=prohibited from importation, movement, sale, purchase, transplanting, cultivation and distribution under CT General Statutes §22a-381d
N/A=not prohibited
Invasive Plant List (Sorted by Botanical Name)
Click here to view the list sorted by COMMON NAME
Acer ginnala – Amur maple (P)
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Amur maple photos
Acer platanoides – Norway maple
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Norway maple photos
Acer pseudoplatanus – Sycamore maple (P)
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Sycamore maple photos
Aegopodium podagraria – Goutweed/Bishops Weed
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Goutweed factsheet
Invasive.org - Goutweed photos
Ailanthus altissima – Tree of Heaven
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Tree of heaven photos
NRCS-1 - Tree of heaven identification sheet
PSU Ext - Tree of heaven factsheet
Alliaria petiolata – Garlic mustard
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Garlic mustard photos
MSU - Garlic mustard factsheet
NRCS-2 - Garlic mustard identification sheet
TNC - Garlic mustard factsheet
Amorpha fruticosa – False indigo (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - False indigo photos
Ampelopsis brevipedunculata – Porcelainberry
Growth form or habit: Woody Vine
Prohibited by statute? N/A
Invasive.org - Porcelainberry photos
NRCS-2 - Porcelainberry identification sheet
Artemisia vulgaris – Mugwort
Growth form or habit: Herbaceous
Prohibited by statute? N/A
NRCS-2 - Mugwort identification sheet
UConn/CIPWG - Mugwort facstsheet
Arthraxon hispidus – Hairy jointgrass (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Hairy jointgrass factsheet
Invasive.org - Hairy jointgrass photos
Bassia scoparia – Common kochia (P)
Berberis thunbergii – Japanese barberry
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - Japanese barberry photos
NRCS-1 - Japanese barberry identification sheet
NRCS-2 - Japanese barberry identification sheet
Maine - Japanese barberry factsheet
Mich State - Japanese barberry factsheet
PA DCNR - Japanese barberry factsheet
UConn IPM - Japanese barberry factsheet
Berberis vulgaris – Common barberry
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Common barberry photos
MDA State - Common barberry factsheet
UMN EXT - Common barberry factsheet
Bromus tectorum – Drooping brome-grass (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Go Botany - Drooping brome-grass
Invasive.org - Drooping brome-grass photos
NRCS - Drooping brome-grass factsheet
PA DCNR - Drooping brome-grass factsheet
Butomus umbellatus – Flowering rush (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Flowering rush factsheet
Invasive.org - Flowering rush photos
Cabomba caroliniana – Fanwort
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Callitriche stagnalis – Pond water-starwort (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Pond water-starwort factsheet
Go Botany - Pond water-starwort
Cardamine impatiens – Narrowleaf bittercress
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Narrowleaf bittercress
Invasive.org - Narrowleaf bittercress factsheet
NRCS-2 - Narrowleaf bittercress identification sheet
PA DCNR - Narrowleaf bittercress photos
UMN EXT - Narrowleaf bittercress factsheet
Carex kobomugi – Japanese sedge (P)
Growth form or habit: Grass of grass-like
Prohibited by statute? Yes
NRCS-2 - Japanese sedge identification sheet
Celastrus orbiculatus – Asiatic bittersweet
Growth form or habit: Woody vine
Prohibited by statute? Yes
Go Botany - Asiatic bittersweet
Invasive.org - Asiatic bittersweet photos
Mich State - Asiatic bittersweet factsheet
NRCS-1 - Asiatic bittersweet identification sheet
PSU - Asiatic bittersweet factsheet
UConn IPM - Asiatic bittersweet factsheet
Centaurea stoebe – Spotted knapweed
Growth form or habit: Herbaceous
Prohibited by statute? Yes
USDA - Spotted knapweed factsheet
PA DCNR - Spotted knapweed factsheet
Cirsium arvense – Canada Thistle (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Canada thistle photo
NRCS-2 - Canada thistle identification sheet
PA DCNR - Canada thistle factsheet
Cynanchum louiseae – Black swallow-wort (syn. Vincetoxicum nigrum)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Black swallow-wort
Invasive.org - Black swallow-wort photos
NRCS-1 - Black swallow-wort identification sheet
PA DCNR - Black swallow-wort factsheet
Cynanchum rossicum – Pale swallow-wort (syn. Vincetoxicum rossicum)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Pale swallow-wort photos
NRCS-1 - Pale swallow-wort identification sheet
PA DCNR - Pale swallow-wort factsheet
UConn IPM - Pale swallow-wort factsheet
Datura stramonium – Jimsonweed (P)
Egeria densa – Brazilian water-weed (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Brazilian water-weed factsheet
CIPWG - Brazilian water-weed photos
Go Botany - Brazilian water-weed
Invasive.org - Brazilian water-weed photos
Maine - Brazilian water-weed factsheet
NRCS-1 - Brazilian water-weed identification sheet
PA DCNR - Brazilian water-weed factsheet
RI DEM - Brazilian water-weed factsheet
Eichhornia crassipes – Common water-hyacinth (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? N/A
CAES - Common water-hyacinth factsheet
Go Botany - Common water-hyacinth
Invasive.org - Common water-hyacinth photos
NRCS-2 - Common water-hyacinth identification sheet
Elaeagnus angustifolia – Russian olive (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Russian olive photos
Maine - Russian olive factsheet
NRCS-1 - Russian olive identification sheet
Elaeagnus umbellata – Autumn olive
Growth form or habit: Shrub
Prohibited by statute? Yes
CIPWG - Autumn olive factsheet
Invasive.org - Autumn olive photos
Maine - Autumn olive factsheet
Mich State - Autumn olive factsheet
NRCS-1 - Autumn olive identification sheet
NRCS-2 - Autumn olive identification sheet
PA DCNR - Autumn olive factsheet
Elsholtzia ciliata – Crested late-summer mint (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Crested late-summer mint
Euonymus alatus – Winged euonymus
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - Winged euonymus photos
NRCS-1 - Winged euonymus identification sheet
Euphorbia cyparissias – Cypress spurge (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Cypress spurge photos
Euphorbia esula – Leafy spurge
Frangula alnus – Glossy buckthorn
Growth form or habit: Shrub
Prohibited by statute? N/A
DEEP - Glossy buckthorn factsheet
Invasive.org - Glossy buckthorn photos
Mich State - Glossy buckthorn factsheet
NRCS-1 - Glossy buckthorn identification sheet
Froelichia gracilis – Slender snake cotton
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Slender snake cotton
Glechoma hederacea – Ground ivy (P)
Glyceria maxima – Reed mannagrass (P)
Growth form or habit: Grass of grass-like
Prohibited by statute? Yes
EDD Maps - Reed mannagrass factsheet
Heracleum mantegazzianum – Giant hogweed (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
CIPWG - Giant hogweed factsheet
Hesperis matronalis – Dame’s rocket
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Humulus japonicus – Japanese hops (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Japanese hops photos
Hydrilla verticillata – Hydrilla
Impatiens glandulifera – Ornamental jewelweed (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
EDD Maps - Ornamental jewelweed factsheet
Go Botany - Ornamental jewelweed
Invasive.org - Ornamental jewelweed photos
NRCS-2 - Ornamental jewelweed identification sheet
Iris pseudacorus – Yellow iris
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Invasive.org - Yellow iris photos
NRCS-2 - Yellow iris identification sheet
Lepidium latifolium – Perennial pepperweed
Growth form or habit: Herbaceous
Prohibited by statute? Yes
EDD Maps - Perennial pepperweed factsheet
Go Botany - Perennial pepperweed
Ligustrum obtusifolium – Border privet (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Border privet photos
Ligustrum ovalifolium – California privet (P)
Growth form or habit: Shrub
Prohibited by statute? N/A
EDD Maps - California privet factsheet
Ligustrum vulgare – European privet (P)
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - European privet photos
Lonicera japonica – Japanese honeysuckle
Growth form or habit: Woody vine
Prohibited by statute? Yes
DEEP - Japanese honeysuckle factsheet
Go Botany - Japanese honeysuckle
Invasive.org - Japanese honeysuckle photos
Maine - Japanese honeysuckle factsheet
NRCS-1 - Japanese honeysuckle identification sheet
NRCS-2 - Japanese honeysuckle identification sheet
PA DCNR - Japanese honeysuckle factsheet
Lonicera maackii – Amur honeysuckle
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Amur honeysuckle photos
Maine - Amur honeysuckle factsheet
NRCS-2 - Amur honeysuckle identification sheet
Lonicera morrowii – Morrow’s honeysuckle
Growth form or habit: Shrub
Prohibited by statute? Yes
Go Botany - Morrow's honeysuckle
Invasive.org - Morrow's honeysuckle photos
Maine - Morrow's honeysuckle factsheet
NRCS-2 - Morrow's honeysuckle identification sheet
PA DCNR - Morrow's honeysuckle factsheet
TNC - Morrow's honeysuckle factsheet
Lonicera tatarica – Tatarian honeysuckle (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Go Botany - Tatarian honeysuckle
Invasive.org - Tatarian honeysuckle photos
Maine - Tatarian honeysuckle factsheet
NRCS-2 - Tatarian honeysuckle identification sheet
Lonicera x bella – Belle honeysuckle
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Belle honeysuckle photos
NRCS-2 - Belle honeysuckle identification sheet
PA DCNR - Belle honeysuckle factsheet
Lonicera xylosteum – Dwarf honeysuckle (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Dwarf honeysuckle photos
Lychnis flos-cuculi – Ragged robin (P)
Lysimachia nummularia – Moneywort (P)
Lysimachia vulgaris – Garden loosestrife (P)
Growth form or habit: Herbacous
Prohibited by statute? Yes
Go Botany - Garden loosestrife
Invasive.org - Garden loosestrife photos
IPANE - Garden loosestrife factsheet
Lythrum salicaria – Purple loosestrife
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Purple loosestrife factsheet
Go Botany - Purple loosestrife
Invasive.org - Purple loosestrife photos
Maine - Purple loosestrife factsheet
NRCS-1 - Purple loosestrife identification sheet
NRCS-2 - Purple loosestrife identification sheet
PA DCNR - Purple loosestrife factsheet
Marsilea quadrifolia – European waterclover (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - European waterclover factsheet
Go Botany - European waterclover
Microstegium vimineum – Japanese stiltgrass
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Go Botany - Japanese stiltgrass
Invasive.org - Japanese stiltgrass photos
NRCS-1 - Japanese stiltgrass identification sheet
NRCS-2 - Japanese stiltgrass identification sheet
NH DoA - Japanese stiltgrass factsheet
PA DCNR - Japanese stiltgrass factsheet
Miscanthus sinensis – Eulalia (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? N/A
Myosotis scorpioides – Forget-me-not
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Forget-me-not factsheet
Invasive.org - Forget-me-not photos
Myriophyllum aquaticum – Parrotfeather (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Parrotfeather factsheet
Invasive.org - Parrotfeather photos
NRCS-1 - Parrotfeather identification sheet
NRCS-2 - Parrotfeather identification sheet
PA DCNR - Parrotfeather factsheet
Myriophyllum heterophyllum – Variable-leaf watermilfoil
Growth form or habit: Aquatic or wetland
Prohibited by statute? Yes
CAES - Variable-leaf watermilfoil factsheet
Go Botany - Variable-leaf watermilfoil
Invasive.org - Variable-leaf watermilfoil photos
NRCS-1 - Variable-leaf watermilfoil identification photos
Myriophyllum spicatum – Eurasian watermilfoil
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Eurasian watermilfoil factsheet
Go Botany - Eurasian watermilfoil
Invasive.org - Eurasian watermilfoil photos
Maine - Eurasian watermilfoil factsheet
NRCS-1 - Eurasian watermilfoil identification sheet
PA DCNR - Eurasian watermilfoil factsheet
Najas minor – Brittle water-nymph (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Brittle water-nymph factsheet
Go Botany - Brittle water-nymph
Nasturtium microphyllum – Onerow yellowcress (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Onerow yellowcress factsheet
EDD Maps - Onerow yellow-cress
Go Botany - Onerow yellow-cress
Nasturtium officinale – Watercress (P)
Growth form or habit: Aquatic or wetland
Prohibited by statute? Yes
Nelumbo lutea – American water lotus (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - American water lotus factsheet
Go Botany - American water lotus
Nymphoides peltata – Yellow floating heart (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Yellow floating heart factsheet
Go Botany - Yellow floating heart
Invasive.org - Yellow floating heart photos
IPANE - Yellow floating heart factsheet
Onopordum acanthium – Scotch thistle (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Scotch thistle photos
Ornithogalum umbellatum – Star-of-Bethlehem (P)
Growth form or habit: Herbaceous
Prohibited by statute? N/A
Invasive.org - Star-of-Bethlehem photos
Paulownia tomentosa – Princess tree (P)
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Princess tree photos
Phalaris arundinacea – Reed canary grass
Growth form or habit: Grass or grass-like
Prohibited by statute? N/A
DNR MN - Reed canary grass factsheet
Invasive.org - Reed canary grass photos
NRCS-2 - Reed canary grass identification sheet
Phragmites australis – Common reed
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Common reed photos
NRCS-1 - Common reed identification sheet
NRCS-2 - Common reed identification sheet
PA DCNR - Common reed factsheet
Pistia stratiotes – Water lettuce (P)
Growth form or habit: Aquatic or wetland
Prohibited by statute? N/A
CAES - Water lettuce factsheet
Poa compressa – Canada bluegrass (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Canada thistle photos
Polygonum caespitosum – Bristled knotweed
Polygonum cuspidatum – Japanese knotweed (syn. Reynoutria japonica and Fallopia japonica)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
DEEP - Japanese knotweed factsheet
Invasive.org - Japanese knotweed photos
Mich State - Japanese knotweed factsheet
NRCS-2 - Japanese knotweed identification sheet
Polygonum perfoliatum (Persicaria perfoliata) – Mile-a-minute vine
Growth form or habit: Herbaceous
Prohibited by statute? Yes
NRCS-1 - MAM identification sheet
Polygonum sachalinense – Giant knotweed (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Giant knotweed photos
Populus alba – White poplar (P)
Potamogeton crispus – Curly-leafed pondweed
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Curly-leaf pondweed factsheet
Go Botany - Curly-leaf pondweed
Invasive.org - Curly-leaf pondweed photos
NRCS-1 - Curly-leaf pondweed identification sheet
PSU EXT - Curly-leaf pondweed factsheet
Pueraria montana – Kudzu (P)
Ranunculus ficaria – Fig buttercup (syn. Ficaria verna)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Fig buttercup photos
Rhamnus cathartica – Common buckthorn
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Common buckthorn photos
Maine - Common buckthorn factsheet
Robinia pseudoacacia – Black locust
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Black locust photos
Rosa multiflora – Multiflora rose
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Multiflora rose photos
Maine - Multiflora rose factsheet
NRCS - Multiflora rose factsheet
NRCS-1 - Multiflora rose identification sheet
NRCS-2 - Multiflora rose identification sheet
PA DCNR - Multiflora rose factsheet
Rosa rugosa – Rugosa rose (P)
Rubus phoenicolasius – Wineberry
Rumex acetosella – Sheep sorrel (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Salvinia molesta – Giant salvinia (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CABI - Giant salvinia factsheet
Senecio jacobaea – Tansy ragwort (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Tansy ragwort photos
WA NWCB - Tansy ragwort factsheet
Silphium perfoliatum – Cup plant (P)
Solanum dulcamara – Bittersweet nightshade (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Bittersweet nightshade
Trapa natans – Water chestnut
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Water chesnut factsheet
Invasive.org - Water chesnut photos
Maine - Water chesnut factsheet
NRCS-1 - Water chesnut identification sheet
NRCS-2 - Water chesnut identification sheet
Tussilago farfara – Coltsfoot
Valeriana officinalis – Garden heliotrope (P)
*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; Minnesota = Minnesota Department of Agriculture; 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