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Noxious weeds

King County, Washington

To offer a suggestion or report an error on the King County Noxious Weeds website, please contact Sasha Shaw, education specialist.

Weed identification photos
Index for identification and control of noxious weeds

Select a plant common name (left) or Latin name (right) from the lists below or click on a thumbnail photo to read individual plant information.

Orange/Yellow flowers

bighead knapweed buffalobur common tansy Dalmatian toadflax dyer's woad
garden loosestrife gorse leafy spurge myrtle spurge orange hawkweed
perennial sowthistle rush skeletonweed Scot's broom Spanish broom common St. Johnswort
sulfur cinquefoil tansy ragwort Texas blueweed velvetleaf yellow hawkweed
yellow starthistle yellow toadflax

Pink/Purple flowers

annual bugloss bittersweet nightshade black knapweed brown knapweed bull thistle
Canada thistle clary sage common bugloss common crupina diffuse knapweed
goatsrue herb Robert kudzu meadow clary meadow knapweed
Mediterranean sage milk thistle musk thistle policeman's helmet purple loosestrife
purple starthistle Russian knapweed saltcedar Scotch thistle slenderflower thistle
spotted knapweed viper's bugloss vochin knapweed wild four o'clock

White/Green flowers

English ivy field bindweed garlic mustard giant hogweed giant knotweed
Himalayan knotweed Japanese knotweed kochia lawnweed old man's beard
oxeye daisy perennial pepperweed poison hemlock Spurge Laurel (Daphne laureola) Syrian bean-caper
wild carrot yellow nutsedge

Aquatic Plants

Brazilian elodea common cordgrass dense-flowered cordgrass Eurasian watermilfoil fanwort
 floating primrose-willow (Ludwigia peploides)
floating
primrose-willow
 fragrant water lily  hydrilla  parrotfeather  phragmites
reed canary grass saltmeadow cordgrass smooth cordgrass water primrose yellow floating heart
yellow flag iris