Advisory List of Invasive Plants - 2019

This is a list of non-native plants found to pose a threat to habitats and natural resources in Maine. The Advisory List is an informal tool for landowners, wildlife biologists, foresters, land stewards, conservation commisions, and others interested in controlling invasive plants and preventing their spread. It is intended for education and outreach, land management, and other non-regulatory uses.

How is the Advisory List different than the Do Not Sell list?

The Do Not Sell list is a regulatory list of terrestrial invasive plants found in the horticulture trade. Plants on the Do Not Sell list may not be imported, exported, bought, sold, or intentionally propagated for sale. An important distinction between the two lists is that the Do Not Sell list only addresses species known from the horticulture trade, while the Advisory List includes numerous species not sold for planting, which are invasive via other pathways. For information on Maine's Regulatory Do Not Sell List, please visit the Maine Horticulture Program's Invasive Plant Rules page.

Common Name Scientific Name Invasive Ranking Habitats Threatened Status in Maine
Amur Cork Tree Phellodendron amurense 2-Very invasive Open Uplands, Wooded Uplands Not Yet Detected
Asiatic bittersweet Celastrus orbiculatus 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Black jetbead Rhodotypos scandens 2-Very invasive Open Uplands, Wooded Uplands Not Yet Detected
Black swallowwort Cynanchum louiseae 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Bohemian knotweed Fallopia x bohemica 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Callery ("Bradford") pear Pyrus calleryana 2-Very invasive Open Uplands, Wooded Uplands Not Yet Detected
Canada thistle Cirsium arvense 1-Severely invasive Open Uplands Widespread
Chinese bindweed Fallopia baldschuanica 3-Invasive, habitat-specific threats Open Uplands Not Yet Detected
Chinese bush-clover Lespedeza cuneata 3-Invasive, habitat-specific threats Open Uplands Not Yet Detected
Chinese yam Dioscorea polystachya 1-Severely invasive Open Uplands, Wooded Wetlands Not Yet Detected
Coltsfoot Tussilago farfara 3-Invasive, habitat-specific threats Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Common barberry Berberis vulgaris 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Common valerian Valeriana officinalis 4-Potential to be invasive, monitor Open Uplands, Open Wetlands, Wooded Wetlands Widespread
Curly pondweed Potamogeton crispus 1-Severely invasive Open Water, Open Wetlands Localized
Dalmation toadflax Linaria dalmatica 3-Invasive, habitat-specific threats Open Uplands, Open Wetlands, Wooded Wetlands Localized
Dame’s rocket Hesperis matronalis 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
False indigo Amorpha fruticosa 1-Severely invasive Open Uplands, Open Wetlands, Wooded Wetlands Localized
Giant hogweed Heracleum mantegazzianum 2-Very invasive Open Wetlands, Wooded Wetlands Localized
Goutweed Aegopodium podagraria 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Hydrilla Hydrilla verticillata 1-Severely invasive Open Water, Open Wetlands Localized
Japanese barberry Berberis thunbergii 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Japanese knotweed Fallopia japonica 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Kudzu Pueraria lobata 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Not Yet Detected
Leafy spurge Euphorbia esula 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands Localized
Mudmat Glossostigma cleistanthum 3-Invasive, habitat-specific threats Open Water, Open Wetlands Not Yet Detected
Multiflora rose Rosa multiflora 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Narrowleaf bittercress Cardamine impatiens 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
Norway maple Acer platanoides 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
One-rowed watercress Nasturtium microphyllum 3-Invasive, habitat-specific threats Open Water Localized
Pale swallowwort Cynanchum rossicum 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Not Yet Detected
Parrot feather Myriophyllum aquaticum 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Privet Ligustrum vulgare 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
Reed canary grass Phalaris arundinacea 1-Severely invasive Open Wetlands, Wooded Wetlands Widespread
Russian olive Elaeagnus angustifolia 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands Not Yet Detected
Spotted knapweed Centaurea stoebe 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands Widespread
Starwort Callitriche stagnalis 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Tree of heaven Ailanthus altissima 1-Severely invasive Open Uplands, Wooded Uplands Localized
Variable milfoil Myriophyllum heterophyllum 1-Severely invasive Open Water, Open Wetlands Localized
Watercress Nasturtium officinale 3-Invasive, habitat-specific threats Open Water Localized
Wavyleaf basketgrass Oplismenus hirtellus ssp. undulatifolius 1-Severely invasive Wooded Uplands, Wooded Wetlands Not Yet Detected
Wood blue grass Poa nemoralis 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Woodland angelica Angelica sylvestris 3-Invasive, habitat-specific threats Open Uplands, Wooded Wetlands Not Yet Detected
American water lotus Nelumbo lutea 1-Severely invasive Open Water, Open Wetlands Localized
Amur honeysuckle Lonicera maackii 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Amur maple Acer ginnala 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Autumn olive Elaeagnus umbellata 2-Very invasive Open Uplands, Wooded Wetlands Widespread
Bella honeysuckle Lonicera x bella 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
Bicolor lespedeza, two-colored bush-clover Lespedeza bicolor 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands Not Yet Detected
Bittersweet or climbing nightshade Solanum dulcamara 4-Potential to be invasive, monitor Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Black locust Robinia pseudoacacia 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Border privet Ligustrum obtusifolium 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
Brazilian waterweed Egeria densa 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Brown knapweed Centaurea jacea 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands, Open Wetlands Widespread
Bull thistle Cirsium vulgare 4-Potential to be invasive, monitor Open Uplands Widespread
California privet Ligustrum ovalifolium 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Not Yet Detected
Canada bluegrass, flat-stemmed bluegrass Poa compressa 5-Not invasive at this time Open Uplands Widespread
Chocolate vine; five-leaf akebia Akebia quinata 1-Severely invasive Open Uplands, Wooded Uplands Not Yet Detected
Common buckthorn Rhamnus cathartica 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Common mugwort Artemisia vulgaris 4-Potential to be invasive, monitor Open Uplands Widespread
Common reed Phragmites australis 1-Severely invasive Open Uplands, Open Wetlands, Wooded Wetlands Widespread
Creeping buttercup Ranunculus repens 2-Very invasive Open Uplands, Open Wetlands, Wooded Wetlands Widespread
Creeping jenny Lysimachia nummularia 4-Potential to be invasive, monitor Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Cypress spurge Euphorbia cyparissias 4-Potential to be invasive, monitor Open Uplands Widespread
English water grass Glyceria maxima 2-Very invasive Open Wetlands Not Yet Detected
Eurasian milfoil Myriophyllum spicatum 1-Severely invasive Open Water, Open Wetlands Localized
European alder Alnus glutinosa 1-Severely invasive Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
European blackberry Rubus fruticosus 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Not Yet Detected
European frog’s bit Hydrocharis morsus-ranae 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
European spindle-tree Euonymus europaeus 6-Insufficient data to evaluate Open Uplands, Wooded Uplands, Wooded Wetlands Localized
False spiraea Sorbaria sorbifolia 6-Insufficient data to evaluate Open Uplands, Wooded Uplands Widespread
Fanwort Cabomba caroliniana 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
February daphne; paradise plant Daphne mezereum 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands Widespread
Fine-leaved sheep fescue Festuca filiformis 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands Widespread
Flowering rush Butomus umbellatus 1-Severely invasive Open Wetlands Localized
Fly honeysuckle Lonicera xylosteum 6-Insufficient data to evaluate Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Garlic mustard Alliaria petiolata 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Giant knotweed Fallopia sachalinensis 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Glossy buckthorn Frangula alnus 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Gray willow Salix cinerea 3-Invasive, habitat-specific threats Open Uplands, Open Wetlands Localized
Great watercress, great yellow-cress Rorippa amphibia 6-Insufficient data to evaluate Open Wetlands Localized
Hairy willow-herb Epilobium hirsutum 2-Very invasive Open Uplands, Open Wetlands Localized
Hardy kiwi Actinidia arguta 2-Very invasive Wooded Uplands, Wooded Wetlands Localized
Inflated bladderwort Utricularia inflata 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Japanese fuki Petasites japonicus 6-Insufficient data to evaluate Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
Japanese honeysuckle Lonicera japonica 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Japanese hops Humulus japonicus 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Japanese stiltgrass Microstegium vimineum 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Not Yet Detected
Japanese tree lilac Syringa reticulata 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands, Wooded Wetlands Not Yet Detected
Lesser celandine Ficaria verna 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Linden arrowwood Viburnum dilatatum 2-Very invasive Open Uplands, Wooded Uplands Not Yet Detected
Mile-a-minute vine Persicaria perfoliata 2-Very invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Not Yet Detected
Morrow’s honeysuckle Lonicera morrowii 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Oriental lady’s thumb smartweed Persicaria longiseta 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Oriental photinia Photinia villosa 2-Very invasive Open Uplands, Open Wetlands, Wooded Wetlands Not Yet Detected
Ornamental jewelweed Impatiens glandulifera 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Porcelainberry Ampelopsis glandulosa 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Localized
Princess tree Paulownia tomentosa 4-Potential to be invasive, monitor Open Uplands, Wooded Uplands Localized
Purple loosestrife Lythrum salicaria 2-Very invasive Open Uplands, Open Wetlands, Wooded Wetlands Widespread
Rugosa rose Rosa rugosa 2-Very invasive Open Uplands Widespread
Siberian elm Ulmus pumila 3-Invasive, habitat-specific threats Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Siebold viburnum Viburnum sieboldii 3-Invasive, habitat-specific threats Open Uplands, Open Wetlands Not Yet Detected
Slender-leaved naiad Najas minor 1-Severely invasive Open Water, Open Wetlands Localized
Small carpgrass Arthraxon hispidus 4-Potential to be invasive, monitor Wooded Wetlands Not Yet Detected
Starry stonewort Nitellopsis obtusa 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Sycamore maple Acer pseudoplatanus 4-Potential to be invasive, monitor Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Tall pepperwort Lepidium latifolium 1-Severely invasive Open Uplands, Open Wetlands Localized
Tartarian honeysuckle Lonicera tatarica 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
Wall lettuce Mycelis muralis 6-Insufficient data to evaluate Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Water chestnut Trapa natans 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Water forget-me-not Myosotis scorpioides 2-Very invasive Open Wetlands, Wooded Wetlands Widespread
Water lettuce Pistia stratiotes 1-Severely invasive Open Water Not Yet Detected
Water soldier Stratiotes aloides 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Western lupine Lupinus polyphyllus 4-Potential to be invasive, monitor Open Uplands, Wooded Uplands, Open Wetlands Widespread
White poplar Populus alba 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Widespread
White Sweet Clover Melilotus albus 7-Not evaluated in 2019 Open Uplands Widespread
Wild Chervil Anthriscus sylvestris 7-Not evaluated in 2019 Open Uplands Localized
Wild parsnip Pastinaca sativa 4-Potential to be invasive, monitor Open Uplands Widespread
Wild thyme Thymus pulegioides 5-Not invasive at this time Open Uplands Widespread
Wineberry Rubus phoenicolasias 1-Severely invasive Open Uplands, Wooded Uplands, Open Wetlands, Wooded Wetlands Not Yet Detected
Winged euonymous Euonymus alatus 1-Severely invasive Open Uplands, Wooded Uplands, Wooded Wetlands Widespread
Wintercreeper Euonymus fortunei 2-Very invasive Open Uplands, Wooded Uplands, Wooded Wetlands Localized
Yam-leaved virgin’s bower Clematis terniflora 2-Very invasive Open Uplands, Wooded Uplands Not Yet Detected
Yellow floating heart Nymphoides peltata 1-Severely invasive Open Water, Open Wetlands Not Yet Detected
Yellow hornpoppy Glaucium flavum 4-Potential to be invasive, monitor Open Wetlands Not Yet Detected
Yellow iris Iris pseudacorus 1-Severely invasive Open Wetlands, Wooded Wetlands Widespread

Please note that this listing of invasive plants is informational only. It is intended to provide the reader with information about these species, including identification and potential control measures. It is not a regulatory list.

Please refer to Title 38, Section §419-C Prevention of the spread of invasive aquatic plants for legislation regarding aquatic invasive plant species in Maine. More information about Chapter 273, the rule for listing invasive terrestrial plants is available at our Horticulture Program.

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