We all share responsibility for protecting Washington from noxious weeds. This site can help you learn how to do your part.

'Noxious weed' is the traditional, legal term for any invasive, non-native plant that threatens agricultural crops, local ecosystems or fish and wildlife habitat.

The term ‘noxious weeds’ includes non-native grasses, flowering plants, shrubs and trees. It also includes aquatic plants that invade wetlands, rivers, lakes and shorelines.

About half of all invasive, noxious weeds are escapees from gardens; the rest are plants accidentally introduced to Washington through human travel and trade.

Noxious Weed Search

    -- Scientific Name -- Abutilon theophrasti Acroptilon repens Adonis annua Aegilops cylindrica Ailanthus altissima Alhagi maurorum Alliaria petiolata Alopecurus myosuroides Ambrosia tomentosa Amorpha fruticosa Anchusa arvensis Anchusa officinalis Anthriscus sylvestris Artemisia absinthium Arum italicum Arundo donax Berteroa incana Brachypodium sylvaticum Bryonia alba Buddleja davidii Butomus umbellatus Cabomba caroliniana Cardaria draba Cardaria pubescens Carduus acanthoides Carduus nutans Carduus pycnocephalus Carduus tenuiflorus Carthamus lanatus Cenchrus longispinus Centaurea calcitrapa Centaurea diffusa Centaurea jacea Centaurea jacea x nigra Centaurea macrocephala Centaurea nigra Centaurea nigrescens Centaurea solstitialis Centaurea stoebe Centaurea tricocephala Chondrilla juncea Cirsium arvense Cirsium vulgare Clematis orientalis Clematis vitalba Conium maculatum Convolvulus arvensis Cortaderia spp. Crucianella angustifolia Crupina vulgaris Cuscuta approximata Cynoglossum officinale Cyperus eragrostis Cyperus esculentus Cytisus scoparius Daphne laureola Daucus carota Dipsacus fullonum Echium vulgare Egeria densa Eichhornia crassipes Epilobium hirsutum Euphorbia esula Euphorbia lathyris Euphorbia myrsinites Euphorbia oblongata Ficaria verna Foeniculum vulgare Galega officinalis Geranium robertianum Geranium lucidum Glyceria maxima Gypsophila paniculata Hedera helix Helianthus ciliaris Hemizonia pungens Heracleum mantegazzianum Hibiscus trionum Hieracium atratum Hieracium aurantiacum Hieracium caespitosum Hieracium floribundum Hieracium glomeratum Hieracium lachenalii Hieracium laevigatum Hieracium pilosella Hieracium piloselloides Hieracium sabaudum Hieracium spp. Hydrilla verticillata Hydrocharis morsus-ranae Hyoscyamus niger Hypericum perforatum Hypochaeris radicata Ilex aquifolium Impatiens capensis Impatiens glandulifera Inula helenium Iris pseudacorus Isatis tinctoria Kochia scoparia Lamiastrum galeobdolon Lepidium latifolium Lepyrodiclis holosteoides Leucanthemum vulgare Linaria dalmatica ssp. dalmatica Linaria vulgaris Ludwigia hexapetala Ludwigia peploides Lysimachia vulgaris Lythrum salicaria Lythrum virgatum Matricaria perforata Mirabilis nyctaginea Myriophyllum aquaticum Myriophyllum heterophyllum Myriophyllum spicatum Nymphaea odorata Nymphoides peltata Onopordum acanthium Phalaris arundinacea Phragmites australis Picris hieracioides Polygonum aubertii Polygonum cuspidatum Polygonum polystachyum Polygonum sachalinense Polygonum x bohemicum Potamogeton crispus Potentilla argentea Potentilla recta Proboscidea louisiana Prunus laurocerasus Pueraria montana var. lobata Rorippa austriaca Rorippa nasturtium-aquaticum Rorippa sylvestris Rosa multiflora Rubus armeniacus Rubus laciniatus Sagittaria graminea Salvia aethiopis Salvia pratensis Salvia sclarea Schoenoplectus mucronatus Secale cereale Senecio jacobaea Senecio vulgaris Silene csereii Silene latifolia ssp. alba Silybum marianum Solanum elaeagnifolium Solanum rostratum Soliva sessilis Sonchus arvensis ssp. arvensis Sorbus aucuparia Sorghum halepense Spartina alterniflora Spartina anglica Spartina densiflora Spartina patens Spartium junceum Sphaerophysa salsula Tamarix ramosissima Tanacetum vulgare Thymelaea passerina Tribulus terrestris Typha angustifolia Ulex europaeus Utricularia inflata Verbena bonariensis Vinca major Vinca minor Xanthium spinosum Zostera japonica Zygophyllum fabago   or...

    -- Common Name -- Absinth Wormwood Annual Bugloss Austrian Fieldcress Baby's Breath Balkan catchfly Bighead Knapweed Black Henbane Black Knapweed Blackgrass blooddrops Blueweed Bohemian Knotweed Brazilian Elodea Brown Knapweed Buffalobur Bull Thistle Butterfly Bush Camelthorn Canada thistle Cereal Rye cherry laurel Clary sage Common Bugloss Common Catsear Common Cordgrass Common Crupina Common Fennel Common Groundsel Common Hawkweed Common Ivy Common Reed Common St. Johnswort Common Tansy common teasel creeping fieldcress Curlyleaf Pondweed Dalmatian Toadflax Dense-Flowered Cordgrass Diffuse Knapweed distaff thistle Dyer's Woad Eggleaf Spurge English holly Eurasian frogs-bit Eurasian Watermilfoil European hawkweed European mountain ash Evergreen Blackberry Fanwort featherhead knapweed Field Bindweed Floating Primrose-Willow Flowering Rush Fragrant Water Lily Garden Loosestrife Garlic Mustard Giant Hogweed Giant Knotweed giant reed Goatsrue Gorse grass-leaved arrowhead Hairy Whitetop Hairy Willow-Herb Hawkweed Oxtongue Hawkweed species Herb-Robert Himalayan Blackberry Himalayan Knotweed Hoary Alyssum Hoary Cress Houndstongue Hydrilla Indigobush Inula Italian arum Italian Thistle Japanese eelgrass* Japanese Knotweed Johnsongrass Jointed Goatgrass Kochia Kudzu large periwinkle Lawn Burweed Leafy Spurge Lepyrodiclis lesser cattail lesser celandine Longspine Sandbur lovegrass sedge Meadow Clary Meadow Knapweed Mediterranean Sage Milk Thistle moleplant Mouseear Hawkweed multiflora rose Musk Thistle Myrtle Spurge narrowleaved crosswort Old Man's Beard Orange Hawkweed oriental clematis Oxeye Daisy pampas grass Parrotfeather Perennial False-Brome Perennial Pepperweed Perennial Sowthistle periwinkle Plumeless Thistle Poison Hemlock Polar Hawkweed Policeman's Helmet Puncturevine Purple Loosestrife Purple Starthistle Queen-Devil Hawkweed Reed Canarygrass Reed Sweetgrass Ricefield Bulrush Rush Skeletonweed Russian Knapweed Salt Meadow Cordgrass Saltcedar Scentless Mayweed Scotch Broom Scotch Thistle Shiny Geranium silverlace vine Silverleaf Nightshade silvery cinquefoil skeleton-leaf bursage Slenderflower Thistle Smooth Cordgrass Smooth Hawkweed Smoothseed Alfalfa Dodder Spanish Broom Spikeweed Spiny Cocklebur spotted jewelweed Spotted Knapweed Spurge Flax Spurge Laurel Sulfur Cinquefoil Swainsonpea swollen bladderwort Syrian Bean-Caper tall hawkweed tall verbena Tansy Ragwort Texas Blueweed tree-of-heaven unicorn-plant Variable-Leaf Milfoil Velvetleaf venice mallow Vochin Knapweed Wand Loosestrife water hyacinth Water Primrose watercress White Bryony White Cockle Wild Carrot Wild Chervil Wild Four o'clock Yellow Archangel Yellow Devil Hawkweed Yellow Flag Iris Yellow Floating Heart Yellow Hawkweed Yellow Nutsedge Yellow Starthistle Yellow Toadflax