Pacific Northwest Noxious Weed List

PNW-IPC List of Invasives as of 1997

Click on column heading to sort the table.

Scientific Name	Common Name	State-Province	Rating
Abutilon theophrasti	Velvetleaf	WA OR BC	A B P
Acaena novae-zelandiae	Biddy-biddy	OR	B
Acroptilon repens (Centaurea repens)	Russian knapweed	WA OR AK BC	B B PR R
Aegilops cylindrica	Jointed goatgrass	WA OR BC	C B P
Aegilops ovata	Ovate	OR	A
Aegilops triuncialis	Barbed	OR	A
Agropyron repens	Quackgrass	OR BC	B R
Alhagi maurorum (Alhagi pseudalhagi)	Camelthorn	WA OR	B A
Alliaria petiolata	Garlic Mustard	WA OR	A B
Alopecurus myosuroides	Blackgrass	WA	B
Alyssum corsicum		OR	A
Alyssum murale	yellow-tuft	OR	A
Amaranthus retroflexus	Redroot Pigweed	BC	N
Ambrosia artemisiifolia	Ragweed	OR	B
Ambrosia tomentosa	Skeletonleaf bursage	OR	A
Amorpha fruticosa	Indigobush	WA	B
Anchusa arvensis	Bugloss, annual	WA	B
Anchusa officinalis	Bugloss, common	WA OR BC	B B R
Anthriscus sylvestris	wild chervil	WA BC	B R
Arctium spp.	Burdock	BC	R
Artemisia absinthium	Absinth wormwood	WA	C
Asclepias speciosa	Showy Milkweed	BC	N
Avena fatua	Wild Oats	BC AK	P R
Berteroa incana	Hoary alyssum	WA BC	B R
Bidens cernua	Nodding Beggar-Ticks	BC	N
Brachypodium sylvaticum	False brome	OR WA	B A
Brassica juncea	big stem mustard	AK	R
Bryonia alba	White bryony	WA OR	B A
Buddleja davidii (except hort. varieties in OR)	Butterfly bush	WA OR	B B
Butomus umbellatus	Flowering rush	WA OR	A A
Cabomba caroliniana	Fanwort	WA	B
Capsella bursa-pastoris	Shepherd's-Purse	BC	N
Cardaria draba	Hoary cress	WA AK	C PR
Cardaria pubescens	Hairy whitetop	WA AK	C PR
Cardaria spp.	Hoary Cress	BC	R
Carduus acanthoides	Thistle, plumeless	WA OR BC	B A R
Carduus nutans	Nodding Thistle, Musk Thistle	WA OR BC	B B N
Carduus pycnocephalus	Italian thistle	WA OR	A B
Carduus tenuiflorus	Slenderflower Thistle	WA OR	A B
Carthamus baeticus	Smooth distaff	OR	A
Carthamus lanatus	Woolly distaff	OR	A
Cenchrus longispinus	Longspine sandbur	WA	B
Centaurea calcitrapa	Purple star thistle	WA OR	A A
Centaurea diffusa	Knapweed, diffuse	WA OR BC	B B P
Centaurea iberica	Iberian	OR	A
Centaurea jacea	Knapweed, brown	WA	B
Centaurea macrocephala	Bighead knapweed	WA	A
Centaurea x moncktonii (Centaurea pratensis, C. jacea x C. nigra)	meadow knapweed	WA OR BC	B B R
Centaurea nigra	Knapweed, black	WA	B
Centaurea nigrescens	Vochin knapweed	WA	A
Centaurea solstitialis	Yellow starthistle	WA OR BC	B B P
Centaurea stoebe (Centaurea maculosa)	spotted knapweed	WA OR AK BC	B B B P
Centaurea virgata	Squarrose knapweed	OR	A
Centraurea nigrescens	Short-fringed Knapweed	WA	A
Chenopodium album	Lamb's-Quarters	BC	N
Chondrilla juncea	Rush skeletonweed	WA OR BC	B B P
Cichorium intybus	Chicory	BC	N
Cicuta douglasii	Water Hemlock	BC	N
Cirsium arvense	Canada Thistle	WA OR AK BC	C B PR P
Cirsium palustre	Marsh Plume Thistle	BC	R
Cirsium vulgare	Bull Thistle	WA OR BC	C B N
Clematis vitalba	Old man's beard	WA OR	C B
Conium maculatum	Poison-hemlock	WA OR	B B
Convolvulus arvensis	Field bindweed	WA OR AK BC	C B PR N
Cortaderia jubata	Jubata grass	OR	B
Crepis tectorum	Narrow-Leaf Hawksbeard	AK
Crupina vulgaris	Common crupina/Bearded creeper	WA OR BC	A B P
Cuscuta approximata	Smoothseed alfalfa dodder	WA	C
Cuscuta japonica	Japanese dodder	OR	A
Cuscuta spp.	Dodder	OR BC	B P
Cynoglossum officinale	Houndstongue	WA OR BC	B B P
Cyperus esculentus	Yellow nutsedge	WA OR BC	B B P
Cyperus rotundus	Purple nutsedge	OR BC	A P
Cytisus scoparius	Scotch broom	WA OR BC	B B N
Cytisus striatus	Portuguese	OR	B
Daphne laureola	Spurge laurel	WA OR	B B
Daucus carota	Wild carrot	WA	B
Dipsacus laciniatus	Cutleaf teasel	OR	B
Echinochloa crusgalli	Barnyardgrass	BC	N
Echium plantagineum	Paterson's curse	OR	A
Echium vulgare	Blueweed	WA BC	B R
Egeria densa (Elodea densa)	South American waterweed/ Brazilian elodea	OR WA	B B
Elymus repens	quack grass	AK	PR
Epilobium hirsutum	Hairy willow-herb	WA	C
Equisetum arvense	Field Horsetail	BC	N
Equisetum telmateia	Giant horsetail	OR	B
Erica lusitanica	Spanish heath	OR	A
Euphorbia esula	Leafy Spurge	WA OR AK BC	B B PR P
Euphorbia myrsinites	Spurge, myrtle	WA OR	B B
Euphorbia oblongata	Eggleaf Spurge	WA OR	A A
Fagopyrum tataricum	Tartary Buckwheat	BC	R
Foeniculum vulgare	Common fennel	WA	B
Galega officinalis	Goatsrue	WA OR	A A
Galensoga parviflora	Galensoga	AK	PR
Galeopsis tetrahit	Hempnettle	AK BC	PR N
Galium aparine	Cleavers	BC	R
Genista monspessulana	French broom	OR	B
Geranium lucidum	shiny geranium	WA OR	A B
Geranium robertianum	Herb-Robert	WA OR	B B
Glyceria maxima	Reed sweetgrass	WA	A
Gnaphalium uliginosum	Cudweed	BC	N
Gypsophila paniculata	Babysbreath	WA BC	C N
Halogeton glomeratus	Halogeton	OR	B
Hedera helix (except named hort varieties)	English ivy	OR	B
Hedera helix 'Baltica’, 'Pittsburgh', and 'Star'; H. hibernica 'Hibernica'	English ivy - four cultivars only	WA	C
Helianthus ciliaris	Texas blueweed	WA OR	A A
Hemizonia pungens	Spikeweed	WA OR	C B
Heracleum mantegazzianum	Giant Hogweed	WA OR BC	A A N
Hieracium atratum	Hawkweed, polar	WA	B
Hieracium aurantiacum	orange hawkweed	WA OR BC AK	B A R PR
Hieracium caespitosum (Hieracium pratense)	Hawkweed, yellow	WA OR	B A
Hieracium floribundum	Yellow Devil Hawkweed	WA OR	A A
Hieracium glomeratum	Hawkweed, queen-devil	WA	B
Hieracium lachenalii	*Hawkweed, common	WA	C
Hieracium laevigatum	Hawkweed, smooth	WA	B
Hieracium pilosella	Hawkweed, mouseear	WA OR	B A
Hieracium piloselloides	King-devil	OR	A
Hieracium spp.	Hawkweeds, nonnative and invasive species not listed elsewhere	WA	C
Hieracium sabaudum	European hawkweed	WA	A
Hordeum jubatum	Foxtail Barley	BC	N
Hydrilla verticillata	Hydrilla	WA OR	A A
Hyocyamus niger	Black henbane	WA	C
Hypericum perforatum	St. Johnswort, common	WA OR BC	C B N
Hypochaeris radicata	Common catsear	WA	B
Impatiens glandulifera	Policeman’s helmet, Himalayan Balsam	WA OR BC	B B N
Iris pseudacorus	Yellow flag iris	WA OR	C B
Isatis tinctoria	Dyers Woad	WA OR	A B
Juncus effusus	Bog Rush	BC	N
Knautia arvensis	Field Scabious	BC	R
Kochia scoparia	kochia	WA OR BC	B B R
Lactuca tatarica subsp. pulchella (Lactuca pulchella)	blue lettuce	AK	PR
Lamiastrum galeobdolon	Yellow archangel	WA	C
Lamium amplexicaule	Henbit	BC	N
Lappula squarrosa (Lappula echinata)	bluebur	AK	R
Lathyrus latifolius	perennial peavine	OR	B
Lepidium chalepensis	Lens-podded	OR	B
Lepidium draba	Hoary cress	OR	B
Lepidium latifolium	Perennial pepperweed	WA OR BC AK	B B R PR
Lepidium pubescens	Hairy	OR	B
Lepyrodiclis holosteoides	lepyrodiclis	WA	B
Leucanthemum vulgare (Chrysanthemum leucanthemum)	oxeye daisy	WA AK BC	B _ R
Linaria dalmatica ssp. dalmatica	Dalmatian toadflax	WA OR BC	B B P
Linaria vulgaris	Yellow toadflax, Butter 'n' Eggs	WA OR AK BC	C B Re P
Ludwigia hexapetala	Water primrose	WA	B
Ludwigia peploides	Floating primrose-willow	WA	A
Lychnis alba	White Cockle	BC	R
Lysimachia vulgaris	Loosestrife, garden	WA	B
Lythrum salicaria	Loosestrife, purple	WA OR AK BC	B B PR R
Lythrum virgatum	Loosestrife, wand	WA	B
Madia glomerata	Cluster Tarweed	BC	N
Malva neglecta	Common Mallow	BC	N
Matricaria maritima	Scentless Chamomile	BC	P
Matricaria matricariodes	Pineappleweed	BC	N
Matricaria perforata	Scentless mayweed	WA	C
Mirabilis nyctaginea	Wild Four O’Clock	WA	A
Myriophyllum aquaticum	Parrotfeather	WA OR	B B
Myriophyllum heterophyllum	variable-leaf watermilfoil	WA	A
Myriophyllum spicatum	Eurasian watermilfoil	WA OR	B B
Nardus stricta	Matgrass	OR	A
Nymphaea odorata	Fragrant water lily	WA	C
Nymphoides peltata	Yellow floating heart	WA OR	B A
Onopordum acanthium	Scotch Thistle	WA OR BC	B B R
Onopordum tauricum	Taurian thistle	OR	A
Orobanche minor	Small broomrape	OR	B
Panicum capillare	Witchgrass	BC	N
Peganum harmala	African rue	OR	A
Persicaria wallichii (Polygonum polystachyum)	Himalayan knotweed	WA OR	B B
Phalaris arundinacea	Reed canarygrass	WA	C
Phragmites australis (nonnative genotypes)	Common reed	WA YT OR	B L A
Picris hieracioides	Hawkweed oxtongue	WA	B
Plantago major	Broad-Leaved Plantain	BC	N
Plantago sp.		AK	R
Poa annua	Annual Bluegrass	BC AK	N R
Poa compressa	Canada blue grass	YT	Po
Poa pratensis	Kentucky blue grass	YT	Po
Polygonum x bohemicum ( Polygonum cuspidatum × sachalinense )	Bohemian knotweed, hybrid Japanese knotweed	WA	B
Polygonum convolvulus	Wild Buckwheat, Black Bindweed	AK BC	Re N
Polygonum cuspidatum (Fallopia japonica)	Fleece flower / knotweed, Japanese	OR WA BC	B B N
Polygonum persicaria	Lady's-Thumb	BC	N
Polygonum sachalinense	giant knotweed	WA OR	B B
Potamogeton crispus	Curly-leaf pondweed	WA	C
Potentilla recta	Sulfur cinquefoil	WA OR BC	B B R
Pueraria montana var. lobata	Kudzu	WA OR	A A
Ranunculus ficaria	lesser celadine	OR	B
Ranunculus repens	creeping buttercup	BC	N
Rorippa austriaca	Austrian fieldcress	WA AK	B PR
Rorippa sylvestris	Creeping yellow cress	OR	B
Rubus armeniacus (R. procerus, R. discolor)	Himalayan blackberry	OR WA	B C
Rubus laciniatus	evergreen blackberry	WA	C
Rumex acetosella	Sheep Sorrel	BC	N
Rumex crispus	Curled Dock	BC	N
Sagittaria graminea	Grass-leaved arrowhead	WA	B
Salsola kali	Russian Thistle	BC	R
Salvia aethiopis	Mediterranean sage	WA OR	A B
Salvia pratensis	Meadow Clary	WA	A
Salvia sclarea	Clary Sage	WA	A
Schoenoplectus mucronatus	ricefield bulrush	WA	A
Secale cereale	Cereal rye	WA	C
Senecio jacobaea	Tansy ragwort	WA OR BC	B B P
Senecio vulgaris	Common groundsel	WA BC	B N
Setaria viridis	Green Foxtail	BC	R
Silene cucubalus	Bladder Campion	BC	N
Silene latifolia ssp. alba	White cockle	WA	C
Silene noctiflora	Night-Flowering Catchfly	BC	R
Silybum marianum	Milk thistle	WA OR	A B
Sinapsis arvensis	Wild Mustard	BC AK	R R
Solanum carolinense	horsenettle	AK	PR
Solanum elaeagnifolium	Silverleaf Nightshade	WA OR	A A
Solanum rostratum	Buffalobur	WA OR	A B
Solanum species	Nightshade	BC	N
Soliva sessilis	lawnweed	WA	B
Sonchus arvensis ssp. arvensis	Perennial sowthistle	WA AK BC	B PR P
Sonchus asper	Spiny Annual Sow-thistle	BC	N
Sonchus oleraceus	Annual Sowthistle	BC	P
Sorghum halepense	Johnsongrass	WA OR	A B
Spartina alterniflora	Smooth cordgrass	WA OR	A A
Spartina anglica	Common cordgrass	OR WA	A A
Spartina densiflora	Dense-flowered cordgrass	WA OR	A A
Spartina patens	Saltmeadow Cordgrass	WA OR	A A
Spartium junceum	Spanish broom	WA OR	A B
Spergula arvensis	Corn Spurry	BC	N
Sphaerophysa salsula	Swainsonpea / Austrian peaweed	WA OR	B B
Stellaria media	Common Chickweed	BC	N
Taeniatherum caput-medusae	Medusahead rye	OR	B
Tamarix ramosissima	Saltcedar	WA OR	B B
Tanacetum vulgare	Common tansy	WA BC	C R
Thlapsi arvense	Stinkweed	BC	N
Thymelaea passerina	Spurge Flax	WA	A
Tragopogon dubius	Western Goat's-Beard	BC	N
Trapa natans	European water chestnut	OR	A
Tribulus terrestris	Puncturevine	WA OR BC	B B R
Tussilago farfara	Coltsfoot	OR	A
Ulex europaeus	Gorse	WA OR BC	B B P
Verbascum thapsus	Mullein	BC	N
Vicia cracca	Tufted Vetch, Bird Vetch	AK	PR
Xanthium spinosum	Spiny cocklebur	WA OR	C B
Zygophyllum fabago	Syrian bean-caper	WA OR	A A

Abbreviations:

British Columbia (BC)
- P = Provincial – Noxious within all Regions of British Columbia
- R = Regional – Noxious within the boundaries of certain regional districts
- N = Nuisance – Weeds not regulated by the BC Weed Control Act
Alaska (AK)
- PR = Prohibited and restricted noxious weeds
- R = Restricted, maximum allowable tolerances of seeds per pound have been calculated
Washington State (WA)
- Class A = Non-native species that are limited in distribution in Washington. State law requires that these weeds be eradicated.
- Class B = Non-native species that are either absent from or limited in distribution in some portions of the state but very abundant in other areas. The goals are to contain the plants where they are already widespread and prevent their spread into new areas.
- Class C = Non-native plants that are already widespread. Counties can choose to enforce control, or they can educate residents about controlling these noxious weeds.
Oregon State (OR)
- A Designated = a weed of known economic importance which occurs in the state in small enough infestations to make eradication or containment possible; or is not known to occur, but its presence in neighboring states make future occurrence in Oregon seem imminent.
- B Designated = a weed of economic importance which is regionally abundant, but which may have limited distribution in some counties.
- T Designated = a priority noxious weed designated by the Oregon State Weed Board as a target on which the Oregon Department of Agriculture will develop and implement a statewide management plan. “T” designated noxious weeds are species selected from either the “A” or “B” list.
Yukon Territories (YT)
- L= low level invasive
- Po=potentially invasive
- H= high invasive

Pacific Northwest Invasive Plant Council

Pacific Northwest Noxious Weed List

Abbreviations: