Phragmites australis ssp. australis along Lower Crab Creek

WA Invasive Ranking System

The presence and abundance of invasive plants are frequently used in function and condition assessment tools. Existing state lists of noxious weeds and invasive species serve valuable purposes, but incorporate economic impacts and other values that don’t always identify the plant species that are most impactful to the ecology of natural ecosystems. With the assistance of regional experts, Washington Natural Heritage Program staff are working to assemble a consistent, defensible list of the most ecologically impactful invasive plant species in Washington State.
 
The Washington Invasive Ranking System (WIRS) is a method for assessing the ecological impact of nonnative plant species in natural ecosystems of Washington State. The primary output of WIRS is an Ecological Impact rank, which indicates the degree of ecological degradation caused by a given plant in the ecosystems in which it is found. WIRS also produces supplementary information related to each plant’s management difficulty, biological characteristics, and distribution and abundance.
 
For complete results for all plants assessed to date, see:
To access individual species assessments, click on the hyperlinked scientific names in the table below.
 
Scientific Name Common Name Ecological Impact Rank
Scientific Name Acer negundo Common Name Box elder Ecological Impact Rank Low
Scientific Name Ailanthus altissima Common Name tree of Heaven Ecological Impact Rank Moderate
Scientific Name Alliaria petiolata Common Name garlic mustard Ecological Impact Rank High
Scientific Name Alopecurus pratensis Common Name field meadow-foxtail Ecological Impact Rank Moderate
Scientific Name Amorpha fruticosa Common Name Indigobush Ecological Impact Rank Moderate
Scientific Name Anthoxanthum odoratum Common Name sweet vernalgrass Ecological Impact Rank Moderate
Scientific Name Arrhenatherum elatius Common Name tall oatgrass Ecological Impact Rank Moderate
Scientific Name Arum italicum ssp. italicum Common Name Italian arum Ecological Impact Rank Low
Scientific Name Arundo donax Common Name giant reed Ecological Impact Rank High
Scientific Name Bellardia viscosa Common Name Yellow glandweed Ecological Impact Rank Low
Scientific Name Bellis perennis Common Name English daisy Ecological Impact Rank Insignificant
Scientific Name Betula pendula Common Name European white birch Ecological Impact Rank Low
Scientific Name Butomus umbellatus Common Name flowering rush Ecological Impact Rank High
Scientific Name Centaurea solstitialis Common Name yellow star-thistle Ecological Impact Rank High
Scientific Name Chondrilla juncea Common Name rush skeletonweed Ecological Impact Rank High
Scientific Name Cirsium arvense Common Name Canada thistle Ecological Impact Rank High
Scientific Name Cirsium vulgare Common Name bull thistle Ecological Impact Rank Low
Scientific Name Clematis vitalba Common Name old man’s beard Ecological Impact Rank Moderate
Scientific Name Cotoneaster spp. Common Name cotoneaster Ecological Impact Rank Low
Scientific Name Crataegus monogyna Common Name English hawthorn Ecological Impact Rank High
Scientific Name Cynoglossum officinale Common Name houndstongue Ecological Impact Rank Moderate
Scientific Name Dianthus armeria Common Name Deptford pink Ecological Impact Rank Insignificant
Scientific Name Dipsacus fullonum Common Name common teasel Ecological Impact Rank Moderate
Scientific Name Erechtites minimus Common Name toothed coast fireweed Ecological Impact Rank Low
Scientific Name Fallopia × bohemica Common Name Bohemian knotweed Ecological Impact Rank High
Scientific Name Hieracium pilosella Common Name mouse-ear hawkweed Ecological Impact Rank Low
Scientific Name Holcus lanatus Common Name common velvetgrass Ecological Impact Rank Moderate
Scientific Name Ilex aquifolium Common Name English holly Ecological Impact Rank High
Scientific Name Impatiens capensis Common Name spotted jewelweed Ecological Impact Rank Low
Scientific Name Iris pseudacorus Common Name yellow flag iris Ecological Impact Rank High
Scientific Name Jacobaea vulgaris Common Name stinking willie Ecological Impact Rank Moderate
Scientific Name Juglans regia Common Name English walnut Ecological Impact Rank Low
Scientific Name Juncus effusus subsp. effusus Common Name common rush Ecological Impact Rank Low
Scientific Name Lamium galeobdolon Common Name yellow archangel Ecological Impact Rank Low
Scientific Name Lathyrus latifolius Common Name everlasting-pea Ecological Impact Rank Low
Scientific Name Lathyrus sylvestris Common Name narrow-leaf pea Ecological Impact Rank Low
Scientific Name Leucanthemum vulgare Common Name oxeye daisy Ecological Impact Rank Moderate
Scientific Name Lysimachia nummularia Common Name garden loosestrife Ecological Impact Rank Low
Scientific Name Lythrum salicaria Common Name purple loosestrife Ecological Impact Rank Moderate
Scientific Name Marrubium vulgare Common Name white horehound Ecological Impact Rank Insignificant
Scientific Name Mycelis muralis Common Name wall lettuce Ecological Impact Rank Insignificant
Scientific Name Myosotis discolor Common Name yellow and blue scorpiongrass Ecological Impact Rank Insignificant
Scientific Name Myriophyllum heterophyllum Common Name variable-leaf milfoil Ecological Impact Rank High
Scientific Name Myriophyllum spicatum Common Name Eurasian watermilfoil Ecological Impact Rank High
Scientific Name Nasturtium officinale Common Name watercress Ecological Impact Rank Moderate
Scientific Name Phalaris arundinacea Common Name reed canarygrass Ecological Impact Rank High
Scientific Name Phleum pratense Common Name Timothy Ecological Impact Rank Low
Scientific Name Plantago lanceolata Common Name English plantain Ecological Impact Rank Insignificant
Scientific Name Poa annua Common Name annual bluegrass Ecological Impact Rank Insignificant
Scientific Name Potamogeton crispus Common Name curlyleaf pondweed Ecological Impact Rank High
Scientific Name Quercus robur Common Name English oak Ecological Impact Rank Low
Scientific Name Rosa canina Common Name dog rose Ecological Impact Rank Moderate
Scientific Name Rosa multiflora Common Name multiflora rose Ecological Impact Rank Moderate
Scientific Name Rosa rugosa Common Name rugosa rose Ecological Impact Rank Low
Scientific Name Rubus bifrons Common Name Himalayan blackberry Ecological Impact Rank High
Scientific Name Rubus laciniatus Common Name cut-leaf blackberry Ecological Impact Rank Moderate
Scientific Name Rumex crispus Common Name curly dock Ecological Impact Rank Insignificant
Scientific Name Sasa palmata Common Name broadleaf bamboo Ecological Impact Rank Moderate
Scientific Name Schedonorus arundinaceus Common Name tall fescue Ecological Impact Rank Moderate
Scientific Name Schoenoplectus mucronatus Common Name ricefield bullrush Ecological Impact Rank Low
Scientific Name Senecio sylvaticus Common Name woodland groundsel Ecological Impact Rank Insignificant
Scientific Name Solanum dulcamara Common Name bittersweet nightshade Ecological Impact Rank Low
Scientific Name Solidago altissima Common Name late goldenrod Ecological Impact Rank Moderate
Scientific Name Spartina alterniflora Common Name smooth cordgrass Ecological Impact Rank High
Scientific Name Tamarix ramosissima Common Name saltcedar Ecological Impact Rank High
Scientific Name Trifolium pratense Common Name red clover Ecological Impact Rank Low
Scientific Name Trifolium subterraneum Common Name burrowing clover Ecological Impact Rank Low
Scientific Name Utricularia inflata Common Name wwollen bladderwort Ecological Impact Rank High
Scientific Name Verbascum blattaria Common Name moth mullein Ecological Impact Rank Insignificant
Scientific Name Veronica anagallis-aquatica Common Name water speedwell Ecological Impact Rank Insignificant
Scientific Name Veronica arvensis Common Name wall speedwell Ecological Impact Rank Insignificant
 

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