Invasive Plant Species

Last edited 2019

By Hubert Ling

As explained in the movie "Jurassic Park" contained within the coils of DNA is one of the mightiest powers on earth. Coded with a simple alphabet of A, T, G, and C is the power to kill billions of organisms, change the gas concentration of the atmosphere, and yes even destroy the whole earth with a Nuclear Winter.

By carelessly shifting around organisms, with their awesome genetic potential, we have caused major ecological disasters. Gone is the most important tree in the Northeast, the American Chestnut, our premier landscaping tree, the American Elm, and gone are huge tracts of productive fresh water marsh. Now these marshes frequently contain extensive acreage with monocultures (only one species present) of purple loosestrife or lesser celandine.

Cornell ecologist David Pimentel has estimated that alien species annually cause $138 billion dollars of damage to our US economy; an estimated 50,000 alien species of insects, plants and other pests now crowd our shores. In 2011 alone, the US Department of the Interior will spend $100 million to attempt to alleviate some of the harmful effects of invasives but that amount has done little to control the problem.

The basic problem is that all organisms have been programmed with a reproductive capacity that can easily outstrip all available resources. This humungous genetic potential is generally held in check by competition with dozens if not hundreds of other organisms, which also have the similar genetic potentials. With so much competition, no one organism takes it all; generally each organism takes only a small share of the total resources of land, water, minerals, light etc.

In addition to direct or indirect competition for resources, disease agents control population growth of any one species. If any one organism grows very well, very large populations develop of that one species. These large populations are very susceptible to attack by disease agents, which include fungi, viruses, and bacteria. Disease agents spread rapidly when their hosts grow close together.

Thus, in any community a dynamic balance is maintained, where populations often ebb and surge but monocultures are rare and populations whose numbers have dwindled are under less stress and eventually recover. Native plants in any given area have adapted to all the other organisms in a given area and genetically diverse ecosystems are generally maintained.

A different scenario takes place when an alien species is transported to a new area. Although direct competition with similar species is still a problem, the new kid in the block may have no natural pests and diseases. Thus, large stands of monocultures can occur. It is generally accepted that one plant species will support 10 species of animals. If one species takes over 99% of a given habitat dozens if not hundreds of species are lost from that area and some populations are stressed enough that extinction is possible.

Humans are responsible for almost all of the invasive plant and animal problems. Many of our problem invasives were (and often still are) planted as landscape plants in New Jersey. These include: Norway Maple, Japanese Barberry, Asian Bittersweet, English Ivy, Mimosa, Wisteria, Japanese Honeysuckle, Bugleweed, Bamboo, Day Lily, Purple Loosestrife, Tansy, and Dame's Rocket.

Only a relatively few commercially important plants such as Teasel, which was used in colonial days to raise the knap on woolen garments and spearmint, show much of a tendency to persist and multiply in the wild. We should probably include in this short list the important pasture clovers: White Sweet, White, and Red as plants which have become so common most people would think that they have been here forever.

Other plants have escaped local and federal projects: Multiflora Rose (previously used as crash barriers along highways, Crown Vetch (still used to stabilize steep hillsides, and Russian and Autumn Olive (used for wildlife habitat support).

We will probably never know how most of the alien plants arrived here. Many may have arrived as contaminating weed seeds along with seed stocks. It is very probable that the following list of plants arrived by that route: Common Mullein, Moth Mullein, Buttercups, Spotted Knapweed, Ox-eye Daisy, Queen Ann's Lace etc.

This list was first issued in 2003. Since that time the list has doubled! If immediate vigorous action is not taken by almost everyone we will lose the war against invasive plants. 

What can you do to help? Plant only native plants! How would you feel if you started a several billion-dollar problem such as Purple Loosestrife? Definitely avoid plants in category 1 - High Risk and category 2 - Moderate Risk and support legislation to restrict these plants. Join the Native Plant society or other conservation groups: New Jersey Invasive Species Strike Team -,  New Jersey Department of Enviroment Protection - Invasive Species Council -,   National Invasive Species Council -,   Smithsonian-,   Nature Conservancy -

Listed below are problem invasive plants for NJ. These lists are not complete and we would like additions, modifications and suggestions.


Category 1 - Strongly Invasive and Widespread
Type Scientific name Common name Photos
Herbaceous Dicots Achillea millefolium Yarrow
Herbaceous Dicots Ajuga reptans Common Bugleweed  
Herbaceous Dicots Alliaria officinalis Garlic Mustard  
Herbaceous Dicots Artemisia vulgaris Mugwort  
Herbaceous Dicots Cardamine impatiens Narrowleaf Bittercress  
Herbaceous Dicots Centaurea maculosa Spotted Knapweed  
Herbaceous Dicots Cichorium intybus Chickory  
Herbaceous Dicots Cirsium arvense Canada Thistle  
Herbaceous Dicots Coronilla varia Crown Vetch  
Herbaceous Dicots Cynanchum nigrum Black Swallow-wort  
Herbaceous Dicots Cynanchum rossicum Pale Swallow-wort  
Herbaceous Dicots Daucus carota Wild Carrot  
Herbaceous Dicots Fallopia sachalinensis Giant Knotweed  
Herbaceous Dicots Ficaria verna Lesser Celandine  
Herbaceous Dicots Glechoma hederacea Gill-Over-The-Ground  
Herbaceous Dicots Hesperis matronalis Dame's Rocket  
Herbaceous Dicots Lespedeza cuneata Sericea Lespedeza  
Herbaceous Dicots Lythrum salicaria Purple Loosestrife  
Herbaceous Dicots Malva moschata Musk Mallow  
Herbaceous Dicots Meliotus alba White Sweet Clover  
Herbaceous Dicots Persicaria perfoliata Mile-A-Minute  
Herbaceous Dicots Plantago lanceolata English Plantain  
Herbaceous Dicots Plantago major Common Plantain  
Herbaceous Dicots Polygonium cuspidatam Japanese Knotweed  
Herbaceous Dicots Ranunculus ficaria Lesser Celandine  
Herbaceous Dicots Rumex crispus Curly Dock  
Herbaceous Dicots Taraxacum officinale Common Dandelion  
Herbaceous Dicots Trifolium pratense Red Clover  
Herbaceous Dicots Trifolium repens White Clover  
Aquatic Dicots Cabomba caroliniana Carolina Fanwort  
Aquatic Dicots Eichhornia crassipes Common Water Hyacinth  
Aquatic Dicots Hydrilla verticillata Hydrilla  
Aquatic Dicots Ludwigia peploides Creeping Waterprimrose  
Aquatic Dicots Myosoton aquaticum Giant Chickweed  
Aquatic Dicots Myriophyllum aquaticum Parrotfeather  
Aquatic Dicots Myriophyllum spicatum Eurasian Water Milfoil  
Aquatic Dicots Potamogeton crispus Curly Pondweed  
Aquatic Dicots Trapa natans European Water Chestnut  
Monocots Allium vineale Field Garlic  
Monocots All bamboo except native cane Any Hardy Bamboo  
Monocots Carex kobomugi Japanese Sedge  
Monocots Carex macrocephala Largehead Sedge  
Monocots Cynodon dactylon Bermuda Grass  
Monocots Dactylis glomerata Orchard Grass  
Monocots Dendrocalamus, etc. Bamboo  
Monocots Digitaria sanguinalis Crab Grass  
Monocots Echinochloa crusgalli Barnyard Grass  
Monocots Eragrostis curvula Weeping Lovegrass  
Monocots Hemercallus fulva Day Lily  
Monocots Iris pseudacorus Yellow Iris  
Monocots Microstegium vimineum Japanese Stilt Grass  
Monocots Miscanthus sinensis Chinese Silvergrass  
Monocots Phalaris canariensis Canarygrass  
Monocots Phragmites australis Common Reed  
Vines & Woody Dicots Acer platanoides Norway Maple  
Vines & Woody Dicots Acer pseudoplatanus Sycamore Maple  
Vines & Woody Dicots Akebia quinata Chocolate Vine  
Vines & Woody Dicots Alianthus altissima Tree Of Heaven  
Vines & Woody Dicots Alnus glutinosa European Black Alder  
Vines & Woody Dicots Ampelopsis brevipedeenculata Porcelainberry  
Vines & Woody Dicots Aralia elata Japanese Angelica Tree  
Vines & Woody Dicots Berberis Thunbergii Japanese Barberry  
Vines & Woody Dicots Celastrus orbiculatus Asian Bittersweet  
Vines & Woody Dicots Clematis flammula Fragrant Clematis  
Vines & Woody Dicots Clematis�terniflora Sweet Autumn Clematis  
Vines & Woody Dicots Cornus kousa Kousa Dogwood  
Vines & Woody Dicots Elaeagnus angustifolia Russian Olive  
Vines & Woody Dicots Elaeagnus umbellata Autumn Olive  
Vines & Woody Dicots Eleutherococcus sieboldianus Five-Leaf Aralia  
Vines & Woody Dicots Euonymus alatus Winged Burning  
Vines & Woody Dicots Frangula alnus Glossy Buckthorn  
Vines & Woody Dicots Hedera helix English Ivy  
Vines & Woody Dicots Ligustrum obtusifolium Border Privet  
Vines & Woody Dicots Ligustrum vulgare European Privet  
Vines & Woody Dicots Lonicera japonica Japanese Honeysuckle  
Vines & Woody Dicots Lonicera maackii Amur Honeysuckle  
Vines & Woody Dicots Lonicera morrowii Fly Honeysuckle  
Vines & Woody Dicots Lonicera tatarica Tatarian Honeysuckle  
Vines & Woody Dicots Malus toringo Japanese Crabapple  
Vines & Woody Dicots Pueraria montana Kudzu  
Vines & Woody Dicots Photinia villosa Oriental Photinia  
Vines & Woody Dicots Prunus subhirtella var. pendula Weeping Higan Cherry  
Vines & Woody Dicots Rhamnus cathartica European Buckthorn  
Vines & Woody Dicots Rhamnus frangula Alder Buckthorn  
Vines & Woody Dicots Rhodotypos scandens Jetbead Rhsc  
Vines & Woody Dicots Rosa multiflora Multiflora Rose  
Vines & Woody Dicots Rosa rugosa Seaside Rose  
Vines & Woody Dicots Rubus phoenicolasius Wine Raspberry  
Vines & Woody Dicots Ulmus procera English Elm  
Vines & Woody Dicots Viburnum dilatatum Linden Viburnum  
Vines & Woody Dicots Viburnum plicatum Japanese Snowball  
Vines & Woody Dicots Viburnum setigerum Tea Viburnum  
Vines & Woody Dicots Viburnum sieboldii Siebold'S Arrowwood  
Vines & Woody Dicots Zelkova serrata Japanese Zelkova  


Category 2, Invasive But Not As Widespread (Yet)
type scientific name common name Photos
Herbaceous Dicots Chelidonium majus Celandine  
Herbaceous Dicots Chrysanthemum leucanthemum Ox-Eye Daisy  
Herbaceous Dicots Dianthus armeria Depford Pink  
Herbaceous Dicots Galinsoga ciliata Galinsoga  
Herbaceous Dicots Lamium purpureum Purple Dead Nettle  
Herbaceous Dicots Linaria vulgaris Butter-And-Eggs  
Herbaceous Dicots Lysimachia nummularia Moneywort  
Herbaceous Dicots Matricaria matricariodes Pineapple Weed  
Herbaceous Dicots Mentha spicata Spearmint  
Herbaceous Dicots Polygonum persicaria Lady's-Thumb  
Herbaceous Dicots Portulaca oleracea Purslane  
Herbaceous Dicots Ranunculus acris Common Buttercup  
Herbaceous Dicots Ranunculus bulbosus Bulbous Buttercup  
Herbaceous Dicots Ranunculus repens Creeping Buttercup  
Herbaceous Dicots Rumex acetosella Sheep's Sorrel  
Herbaceous Dicots Rumex obtusifolius Broad Dock  
Herbaceous Dicots Tanacetum vulgare Tansy  
Herbaceous Dicots Verbascum blattaria Moth Mullein  
Herbaceous Dicots Verbascum thapsus Common Mullein  
Monocots Commelina communis Day Flower  
Vines & Woody Dicots Albizia julibrissin Mimosa  
Vines & Woody Dicots Buddleja davidii Butterfly Bush  
Vines & Woody Dicots Prunus avium Crab Cherry  
Vines & Woody Dicots Wisteria floribunda Wisteria  
Vines & Woody Dicots Wisteria frutescens Wisteria