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King County, Washington noxious weed identification and control

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Regulated Class B noxious weeds, 2013 list
(control is required for these species in King County)

Common name

 Scientific name
blueweed, viper's bugloss (external link)  Echium vulgare
Brazilian elodea (see note 1 below) Egeria densa
bugloss, annual Anchusa arvensis
bugloss, common Anchusa officinalis
camelthorn (external link)  Alhagi maurorum
common reed (non-native genotypes) Phragmites australis
Dalmatian toadflax Linaria dalmatica ssp. dalmatica
fanwort Cabomba caroliniana
gorse Ulex europaeus
grass-leaved arrowhead (external link) Sagittaria graminea
hairy willowherb Epilobium hirsutum
hawkweed oxtongue (external link) Picris hieracioides
hawkweed, mouseear (external link) Hieracium pilosella
hawkweed, orange Hieracium aurantiacum
hawkweed, queen-devil (external link) Hieracium glomeratum
hawkweed, smooth (external link) Hieracium laevigatum
hawkweed, tall Hieracium piloselloides
hawkweed, yellow Hieracium caespitosum
hoary alyssum (external link) Berteroa incana
houndstongue Cynoglossum officinale
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
loosestrife, garden Lysimachia vulgaris
loosestrife, purple Lythrum salicaria
parrotfeather Myriophyllum aquaticum
perennial pepperweed Lepidium latifolium
policeman's helmet Impatiens glandulifera
rush skeletonweed Chondrilla juncea
saltcedar Tamarix ramosissima
spurge, leafy Euphorbia esula
sulfur cinquefoil Potentilla recta
tansy ragwort (see note 2 below) Senecio jacobaea
thistle, musk Carduus nutans
thistle, plumeless (external link) Carduus acanthoides
thistle, Scotch Onopordum acanthium
water primrose Ludwigia hexapetala
white bryony (external link) Bryonia alba
wild chervil (external link) Anthriscus sylvestris
yellow floating heart Nymphoides peltata
yellow nutsedge Cyperus esculentus
yellow starthistle Centaurea solstitialis
1. Brazilian elodea is designated for control throughout King County except in Lake Washington, Lake Sammamish, Lake Union, Lake Fenwick, Lake Doloff and the Sammamish River.
2. Tansy ragwort is not designated by the State Weed Board for control in King County, but has been selected by the King County Weed Board for required control in all areas of King County.

King County Noxious Weed List

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Related information

Related 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.