The following are considered prohibited noxious weeds for the purpose of seed certification.
english or common name | botanical or scientific name |
Austrian fieldcress | Rorippa austriaca |
Field bindweed | Convolvulus arvensis |
Hedge bindweed | Calystegia spp. |
Camelthorn | Alhagi maurorum |
Canada thistle | Cirsium arvense |
Dodder | Cuscuta spp. |
Hairy whitetop | Lepidium appelianum |
Hoary cress | Lepidium draba |
Jointed goatgrass and jointed goatgrass hybrids | Aegilops cylindrica |
Leafy spurge | Euphorbia esula |
Palmer amaranth | Amaranthus palmeri |
Perennial pepperweed | Lepidium latifolium |
Perennial sowthistle | Sonchus arvensis |
Quackgrass | Elymus repens |
Knapweed complex: | |
Bighead | Centaurea macrocephala |
Vochin | Centaurea nigrescens |
Black | Centaurea nigra |
Brown | Centaurea jacea |
Diffuse | Centaurea diffusa |
Meadow | Centaurea x moncktonii |
Russian | Rhaponticum repens |
Spotted | Centaurea stoebesubsp. australis |
Purple starthistle | Centaurea calcitrapa |
Yellow starthistle | Centaurea solstitialis |
Serrated tussock | Nassella trichotoma |
Silverleaf nightshade | Solanum elaeagnifolium Cav. |
Sorghum perennial such as, but not limited to, johnsongrass, columbus grass, and perennial sweet sudangrass | Sorghum spp. Sorghum halepense Sorghum almum Sorghum bicolor (L.) Moench ssp. drummondii |
Tansy ragwort | Jacobaea vulgaris |
Yellow-flowering skeleton weed | Chondrilla juncea |
White cockle | Silene latifolia (only in timothy) |
Bladder campion | Silene vulgaris (only in timothy) |
Lepyrodiclis | Lepyrodicilis holosteoides |
Velvetleaf, Butterprint | Abutilon theophrasti |
[Statutory Authority: RCW 15.49.005, [15.49].021, [15.49].310, [15.49].370, 15.140.030, and chapter 15.49 RCW. WSR 25-09-035, s 16-302-100, filed 4/9/25, effective 5/10/25. Statutory Authority: RCW 15.49.005, [15.49].021, [15.49].310, [15.49].370, and chapter 34.05 RCW. WSR 18-19-017, § 16-302-100, filed 9/10/18, effective 10/11/18. Statutory Authority: RCW 15.49.005, 15.49.081, 15.49.310, 15.49.370(3), and chapter 34.05 RCW. WSR 14-20-050, § 16-302-100, filed 9/25/14, effective 10/26/14. Statutory Authority: Chapter 15.49 RCW. WSR 09-16-006, § 16-302-100, filed 7/22/09, effective 8/22/09. Statutory Authority: RCW 15.49.005, 15.49.081, 15.49.310, 15.49.370(3) and chapter 17.24 RCW. WSR 00-24-077, § 16-302-100, filed 12/4/00, effective 1/4/01.]