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Class B Noxious Weeds, 2009 List
(control required in King County)

Common Name

Scientific Name
Austrian fieldcress Rorippa austriaca
blackgrass Alopecurus myosuroides
blueweed, viper's bugloss Echium vulgare
Brazilian elodea* Egeria densa
bugloss, annual Anchusa arvensis
bugloss, common Anchusa officinalis
camelthorn Alhagi maurorum
common reed (non-native genotypes) Phragmites australis
Dalmatian toadflax Linaria dalmatica ssp. dalmatica
fanwort Cabomba caroliniana
gorse Ulex europaeus
grass-leaved arrowhead Sagittaria graminea
hawkweed, oxtongue Picris hieracioides
hawkweed, mouseear Hieracium pilosella
hawkweed, orange Hieracium aurantiacum
hawkweed, polar Hieracium atratum
hawkweed, queen-devil Hieracium glomeratum
hawkweed, smooth Hieracium laevigatum
hawkweed, yellow Hieracium caespitosum
hoary alyssum Berteroa incana
knapweed, black Centaurea nigra
knapweed, brown Centaurea jacea
knapweed, diffuse Centaurea diffusa
knapweed, meadow Centaurea jacea x nigra
knapweed, Russian Acroptilon repens
knapweed, spotted Centaurea stoebe
kochia Kochia scoparia
lepyrodiclis Lepyrodiclis holosteoides
longspine sandbur Cenchrus longispinus
loosestrife, garden Lysimachia vulgaris
loosestrife, purple Lythrum salicaria
parrotfeather Myriophyllum aquaticum
perennial pepperweed Lepidium latifolium
perennial sowthistle Sonchus arvensis
policeman's helmet Impatiens glandulifera
rush skeletonweed Chondrilla juncea
saltcedar Tamarix ramosissima
spurge, leafy  Euphorbia esula
sulfur cinquefoil Potentilla recta
swainsonpea Sphaerophysa salsula
tansy ragwort Senecio jacobaea
thistle, musk Carduus nutans
thistle, plumeless Carduus acanthoides
thistle, Scotch Onopordum acanthium
water primrose Ludwigia hexapetala
white bryony Bryonia alba
wild chervil Anthriscus sylvestris
yellow floating heart Nymphoides peltata
yellow nutsedge Cyperus esculentus
yellow starthistle Centaurea solstitialis
*Brazilian elodea is designated for control throughout King County except in Lake Washington, Lake Sammamish, Lake Union and Lake Fenwick.

King County Noxious Weed List

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Agencies

Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. To contact a staff member at the King County Noxious Weed Control Program, please call 206-296-0290 or by reach them by email.