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CONNECTICUT INVASIVE PLANT LIST
JANUARY 2004

   This is a list of species that have been determined by floristic analysis to be invasive or potentially invasive in the state of Connecticut, in accordance with PA 03-136.  The Invasive Plants Council will generate a second list recommending restrictions on some of these plants.  In developing the second list and particular restrictions, the Council will recognize the need to balance the detrimental effects of invasive plants with the agricultural and horticultural value of some of these plants, while still protecting the state's minimally managed habitats.

CONNECTICUT INVASIVE PLANT LIST
( Produced by the Connecticut Invasive Plants Council ) 
Connecticut Public Act No. 03-136

The Connecticut Invasive Plants Council encourages the use of non-invasive alternatives, particularly when planting near parks, natural areas, or other minimally managed habitats.

AQUATIC & WETLAND PLANTS

Species  

Common name

Invasive  

Potentially Invasive  

Butomus umbellatus L.

Flowering rush

X

Cabomba caroliniana A. Gray

Fanwort

X

Callitriche stagnalis Scop.

Pond water-starwort

X

Egeria densa Planchon

Brazilian water-weed

X

†Eichhornia crassipes (Mart.) Solms

Common water-hyacinth

X

Hydrilla verticillata (L.f.) Royle

Hydrilla

X

Iris pseudacorus L.

Yellow Iris

X

Lythrum salicaria L.

Purple loosestrife

X

Marsilea quadrifolia L.

European waterclover

X

Myosotis scorpioides L.

Forget-me-not

X

Myriophyllum aquaticum (Vell.) Verdc.

Parrotfeather

X

Myriophyllum heterophyllum Michx.

Variable-leaf watermilfoil

X

Myriophyllum spicatum L.

Eurasian watermilfoil

X

Najas minor All.

Brittle water-nymph

X

Nelumbo lutea (Willd.) Pers.

American water lotus

X

†Nymphoides peltata (Gmel.) Kuntze

Yellow floating heart

X

†Pistia stratiotes L.

Water lettuce

X

Potamogeton crispus L.

Crispy-leaved pondweed

X

Rorippa microphylla (Boenn. ex Reichenb.) Hyl. ex A. & D. Löve

Onerow yellowcress

X

Rorippa nasturtium-aquaticum (L.) Hayek

Watercress

X

†Salvinia molesta Mitchell complex

Giant salvinia

X

Trapa natans L.

Water chestnut

X

TREES

 Species

Common name

Invasive

Potentially Invasive

Acer ginnala L.

Amur maple

X

*Acer platanoides L.

Norway maple

X

Acer pseudoplatanus L.

Sycamore maple

X

Ailanthus altissima (Mill.) Swingle

Tree of heaven

X

Paulownia tomentosa (Thunb.) Steudel

Princess tree

X

Populus alba L.

White poplar

X

*Robinia pseudo-acacia L.

Black locust

X

SHRUBS

 Species

Common name

Invasive

Potentially Invasive

Amorpha fruticosa L.

False indigo

X

*Berberis thunbergii DC.

Japanese barberry

X

Berberis vulgaris L.

Common barberry

X

Elaeagnus angustifolia L.

Russian olive

X

Elaeagnus umbellata Thunb.

Autumn olive

X

*Euonymus alatus (Thunb.) Sieb.

Winged euonymus

X

Frangula alnus Mill.

Glossy buckthorn

X

Ligustrum obtusifolium Sieb. & Zucc.

Border privet

X

Ligustrum ovalifolium Hassk.

California privet

X

Ligustrum vulgare L.

European privet

X

Lonicera ×bella Zabel

Bell's honeysuckle

X

Lonicera maackii (Rupr.) Maxim.

Amur honeysuckle

X

Lonicera morrowii A. Gray

Morrow's honeysuckle

X

Lonicera tatarica L.

Tatarian honeysuckle

X

†Lonicera xylosteum L.

Dwarf honeysuckle

X

Rhamnus cathartica L.

Common buckthorn

X

Rosa multiflora Thunb.

Multiflora rose

X

*Rosa rugosa Thunb.

Rugosa rose

X

Rubus phoenicolasius Maxim.

Wineberry

X

 

WOODY VINES

 Species

Common name

Invasive

Potentially Invasive

*Ampelopsis brevipedunculata (Maxim.) Trautv.

Porcelainberry

X

Celastrus orbiculatus Thunb.

Oriental bittersweet

X

*Lonicera japonica Thunb.

Japanese honeysuckle

X

Pueraria montana (Lour.) Merr.

Kudzu

X

HERBACEOUS PLANTS

 Species

Common name

Invasive

Potentially Invasive

Aegopodium podagraria L.

Goutweed

X

Alliaria petiolata (Bieb.) Cavara & Grande

Garlic mustard

X

Cardamine impatiens L.

Narrowleaf bittercress

X

Centaurea biebersteinii DC.

Spotted knapweed

X

Cirsium arvense (L.) Scop.

Canada thistle

X

Cynanchum louiseae Kartesz & Gandhi

Black swallow-wort

X

Cynanchum rossicum (Kleo.) Borhidi

Pale swallow-wort

X

Datura stramonium L.

Jimsonweed

X

Elsholtzia ciliata (Thunb.) Hylander

Crested late-summer mint

X

Euphorbia cyparissias L.

Cypress spurge

X

Euphorbia esula L.

Leafy spurge

X

Froelichia gracilis (Hook.) Moq.

Slender snake cotton

X

Glechoma hederacea L.

Ground ivy

X

Heracleum mantegazzianum Sommier & Lavier

Giant hogweed

X

Hesperis matronalis L.

Dame's rocket

X

Humulus japonicus Sieb. & Zucc.

Japanese hops

X

†Impatiens glandulifera Royle

Ornamental jewelweed

X

Kochia scoparia (L.) Schrader

Common kochia

X

Lepidium latifolium L.

Perennial pepperweed

X

Lychnis flos-cuculi L.

Ragged robin

X

*Lysimachia nummularia L.

Moneywort

X

*Lysimachia vulgaris L.

Garden loosestrife

X

Onopordum acanthium L.

Scotch thistle

X

Ornithogalum umbellatum L.

Star-of-Bethlehem

X

Polygonum caespitosum Blume

Bristled knotweed

X

Polygonum cuspidatum Sieb. & Zucc.

Japanese knotweed

X

Polygonum perfoliatum L.

Mile-a-minute vine

X

Polygonum sachalinense F. Schmidt ex Maxim.

Giant knotweed

X

Ranunculus ficaria L.

Fig buttercup

X

Rumex acetosella L.

Sheep sorrel

X

†Senecio jacobaea L.

Tansy ragwort

X

Silphium perfoliatum L.

Cup plant

X

Solanum dulcamara L.

Bittersweet nightshade

X

Tussilago farfara L.

Coltsfoot

X

Valeriana officinalis L.

Garden heliotrope

X

GRASSES AND GRASS-LIKE PLANTS

 Species

Common name

Invasive

Potentially Invasive

Arthraxon hispidus (Thunb.) Makino

Hairy jointgrass

X

Bromus tectorum L.

Drooping brome-grass

X

†Carex kobomugi Owhi

Japanese sedge

X

Glyceria maxima (Hartman) Holmburg

Reed mannagrass

X

Microstegium vimineum (Trin.) A. Camus

Japanese stilt grass

X

*Miscanthus sinensis Anderss.

Eulalia

X

Phalaris arundinacea L.

Reed canary grass

X

Phragmites australis (Cav.) Trin.

Common reed

X

Poa compressa L.

Canada bluegrass

X

* An asterisk (*) denotes that the species, although shown by scientific evaluation to be invasive, has cultivars that have not been evaluated for invasive characteristics.  Further research may determine whether or not individual cultivars are potentially invasive.  Cultivars are commercially available selections of a plant species that have been bred or selected for predictable, desirable attributes of horticultural value such as form (dwarf or weeping forms), foliage (variegated or colorful leaves), or flowering attributes (enhanced flower color or size).

† A dagger (†) indicates species that are not currently known to be naturalized in Connecticut but would likely become invasive here if they are found to persist in the state without cultivation.

January 2004