Wash. Admin. Code § 16-301-045
Prohibited noxious weed seeds are the seeds of weeds which when established are highly destructive, competitive and/or difficult to control by cultural or chemical practices. Seed is deemed mislabeled if the seed consists of or contains any of the prohibited noxious weed seeds listed below. For the purpose of seed certification, see WAC 16-302-100 for the list of prohibited noxious weeds.
| ENGLISH OR COMMON NAME | BOTANICAL OR SCIENTIFIC NAME |
| Austrian fieldcress | Rorippa austriaca |
| Field bindweed | Convolvulus arvensis |
| Hedge bindweed | Calystegia sepium |
| Bladder campion | Silene vulgaris |
| (only in timothy- Phleum pratense) | |
| Camelthorn | Alhagi maurorum |
| Canada thistle | Cirsium arvense |
| Hairy whitetop | Lepidium appelianum |
| Hoary cress | Lepidium draba |
| Jointed goatgrass | Aegilops cylindrica |
| (only in small grain) | |
| Knapweed complex | |
| (including bighead, | Centaurea macrocephala, |
| Vochin, | Centaurea nigrescens, |
| black, | Centaurea nigra, |
| brown, | Centaurea jacea, |
| diffuse, | Centaurea diffusa, |
| meadow, | Centaurea x moncktonii, |
| Russian, | Rhaponticum repens, |
| spotted knapweeds | Centaurea stoebe subsp. australis, |
| Purple starthistle) | Centaurea calcitrapa |
| Leafy spurge | Euphorbia esula |
| Lepyrodiclis | Lepyrodiclis holosteoides |
| Palmers amaranth | Amaranthus palmeri |
| Perennial pepperweed | Lepidium latifolium |
| Perennial sowthistle | Sonchus arvensis |
| Quackgrass | Elymus repens |
| Serrated tussock | Nassella trichotoma |
| Silverleaf nightshade | Solanum elaeagnifolium |
| Sorghum perennial such as, but not limited to, | Sorghum spp. |
| johnsongrass, | |
| sorghum almum, and | |
| perennial sweet sudangrass | |
| Tansy ragwort | Jacobaea vulgaris |
| Velvetleaf | Abutilon theophrasti |
| White cockle | Silene latifloia |
| (only in timothy- | |
| Phleum pratense) | |
| Yellow-flowering skeleton weed | Chondrilla juncea |
| Yellow starthistle | Centaurea solstitialis |
Wash. Admin. Code § 16-301-045
Statutory Authority: Chapter 15.49 RCW. 09-16-006, § 16-301-045, filed 7/22/09, effective 8/22/09. Statutory Authority: Chapters 15.49 and 34.05 RCW. 02-12-060, § 16-301-045, filed 5/30/02, effective 6/30/02. Statutory Authority: RCW 15.49.005, 15.49.081, 15.49.310, 15.49.370(3) and chapter 17.24 RCW. 00-24-077, § 16-301-045, filed 12/4/00, effective 1/4/01.