Plants becoming invasive in Wisconsin

"A weed is a plant
that is not only in the wrong place,
but intends to stay."
~by Sara Stein

The Invasive Plant Association of Wisconsin's (IPAW)  mission is to promote better stewardship of the natural resources of Wisconsin by advancing the understanding of invasive plants and encouraging the control of their spread. Invasive plants invade native plant communities and wild areas, and displace or replace native vegetation, thereby threatening the entire native ecosystem. The goal of the organization is to restore natural communities and vegetation.

http://www.ipaw.org/

Weeds and invasive plants are "plants out of place", but an invasive plants encroach into forests, roadsides, and prairies.  Ironically, many invasive plants get their foothold through well-meaning gardeners who introduce the species as a lovely accent to their gardens. Many of these plants come from foreign lands and do not have the natural controls here that a native plant has, taking over  the garden and then, by propagating via the wind, through deep-set runners and by the cooperation of willing birds carrying the seeds, more distant places.

IPAW's Working List of Invasive Plants of Wisconsin

Scientific Name	Common Name	Obs	Mean  Impact	Mean  Dist Level	Growth Form
Acer platanoides	Norway maple	15	3.75	10.1785	Tree
Alliaria petiolata	Garlic Mustard	44	9.375	12.5595	Forb
Arctium minus	Common burdock	38	3.2638	6.3888	Forb
Berberis thunbergii	Japanese barberry	29	3.75	10.7142	Shrub
Bromus inermis	Smooth brome	36	6.4705	9.9285	Grass
Campanula rapunculoides	Creeping bellflower	11	3.6363	5.6818	Forb
Celastrus orbiculatus	Oriental bittersweet	14	6.25	9.423	Vine
Centaurea maculosa	Spotted knapweed	44	7.5	6.4285	Forb
Cirsium arvense	Canada thistle	44	6.25	6.5625	Forb
Convallaria majalis	Lily-of-the-valley	13	5.7692	10.2083	Forb
Convolvulus arvensis	Field bindweed	24	2.2727	5.0	Forb, Vine
Cornilla varia	Crown vetch	37	7.9166	7.6428	Forb, Vine
Crepis tectorum	Hawksbeard	13	3.8636	5.0	Forb
Daucus carota	Queen Annes lace	38	3.7857	6.9117	Forb
Dipsacus laciniatus	Cut-leaved teasel	15	7.0	6.7857	Forb
Dipsacus sylvestris	Common teasel	18	5.8333	5.9722	Forb
Elaeagnus angustifolia	Russian olive	15	4.2307	8.125	Tree, Shrub
Elaeagnus umbellata	Autumn olive	19	6.6666	8.3333	Shrub
Elytrigia repens	Quackgrass	30	5.6034	7.3214	Grass
Epipactis helleborine	Helleborine orchid	12	2.5	11.75	Forb
Euphorbia cyparissias	Cypress spurge	18	5.4166	8.3333	Forb
Euphorbia esula	Leafy spurge	29	8.2692	8.4615	Forb
Festuca elatior	Tall fescue	10	5.625	8.0555	Grass
Glechoma hederacea	Creeping Charlie	19	3.8235	7.5	Forb
Hemerocallis fulva	Orange daylily	13	5.0	7.2727	Forb
Hesperis matronalis	Dame's rocket	33	5.8593	8.5483	Forb
Hieracium aurantiacum	Orange hawkweed	28	4.4444	9.7222	Forb
Hieracium caespitosum	Yellow hawkweed	11	4.0	8.5	Forb
Hypericum perforatum	St. John's wort	32	2.3333	7.9464	Forb
Iris pseudacorus	Yellow iris	15	3.5714	8.75	Forb
Leonurus cardiaca	Motherwort	19	2.5	5.9722	Forb
Lonicera maackii	Amur honeysuckle	13	8.3333	10.8333	Shrub
Lonicera morrowii	Morrow's honeysuckle	21	8.375	11.5789	Shrub
Loricera tatarica	Tartarian honeysuckle	33	8.5156	11.0156	Shrub
Lonicera x bella	Bell's honeysuckle	14	8.9285	12.3214	Shrub
Lotus corniculatus	Bird's-foot trefoil	32	4.7656	5.4687	Forb
Lysimachia nummularia	Moneywort	12	5.6818	10.625	Forb
Lythrum salicaria	Purple loosestrife	45	9.3181	11.6279	Forb
Melilotus alba	White sweet clover	41	6.9078	9.5394	Forb
Melilotus officinalis	Yellow sweet clover	41	6.6025	9.5394	Forb
Morus alba	White mulberry	15	2.8333	8.1666	Tree
Myosotis scorpioides	Forget-me-not	17	4.375	8.75	Forb
Myriophyllum spicatum	Eurasian watermilfoil	25	9.2708	11.7391	Forb
Pastinaca sativa	Wild parsnip	40	6.625	8.9473	Forb
Phalaris arundinacea (nn)	Reed canary grass (nn)	47	9.8936	11.6489	Grass
Phragmites australis (nn)	Common reed grass (nn)	16	8.4375	9.2187	Grass
Pinus sylvestris	Scotch pine	13	2.6923	9.1666	Tree
Poa compressa	Canada bluegrass	23	2.5	10.5681	Grass
Poa pratensis	Kentucky bluegrass	34	4.7656	10.0	Grass
Polygonum cuspidatum	Japanese knotweed	17	7.6562	5.1562	Forb
Populus alba	White poplar	10	5.5	8.5	Tree
Potamogeton crispus	Curly-leaf pondweed	18	5.3333	12.5	Forb
Rhamnus cathartica	Common buckthorn	40	9.2763	12.0394	Shrub, Tree
Rhamnus frangula	Glossy buckthorn	25	8.9583	12.7083	Shrub
Robinia pseudoacacia	Black locust	33	7.5	10.9375	Tree
Rosa multiflora	Multiflora rose	27	6.5384	10.4166	Shrub
Rumex acetosella	Sheep sorrel	21	3.1578	7.7631	Forb
Saponaria officinalis	Soapwort	19	3.3333	6.3888	Forest
Solanum dulcamara	Climbing nightshade	19	3.3333	7.9166	Forb
Tanacetum vulgare	Tansy	22	4.2105	5.125	Forb
Trifolium pratense	Red clover	29	3.1	6.7307	Forest
Trifolium repens	White clover	29	2.9	5.673	Forest
Typha angustifolia	Narrow-leaved cattail	21	7.375	9.125	Forest
Typha x glauca	Hybrid cattail	11	7.7272	9.0909	Forest
Ulmus pumila	Siberian elm	17	4.8437	7.9687	Tree, Shrub
Vinca minor	Common periwinkle	10	6.875	7.5	Forb, Vine

Obs	Observations	The number of survey respondents.
Mean Impact	Mean Impact	The average scores for the variables.
		0 = Little or no ecological impact
		10 = Invades and replaces native communities
Mean Dist Level	Mean Disturbance Level	The average scores for the variables.
		0 = Only in sites disturbed within the last 3 years
		20 = In high-quality, undisturbed natural areas