Click on the common name of the noxious weed below and you will be directed to the Colorado Department of Agriculture's description of that species. 

Once you are on the CDA species description page, be sure to CLICK ON THE SPECIES FACT SHEET (PDF) for the complete description and herbicide recommendations.   

List “A” Species

Cypress Spurge (Euphorbia cyparissias)     

Orange hawkweed (Hieracium aurantiacum)             

List “B” Species

Black henbane (Hyoscyamus niger) 

Bull thistle (Cirsium vulgare)

Canada thistle (Cirsium arvense) 

Chamomile Daisy: Scentless and Mayweed  (Tripleurospermum perforatum and Anthemis cotula)

Common tansy (Tanacetum vulgare) 

Dalmatian toadflax (Linaria dalmatica) 

Dame’s rocket (Hesperis matronalis) 

Diffuse knapweed (Centaurea diffusa) 

Hoary cress/Whitetop (Cardaria draba) 

Houndstongue (Cynoglossum officinale) 

Leafy spurge (Euphorbia esula) 

Musk thistle (Carduus nutans) 

Oxeye daisy (Leucanthemum vulgare) 

Perennial pepperweed (Lepidium latifolium) 

Plumeless thistle (Carduus acanthoides) 

Russian knapweed (Acroptilon repens) 

Scotch thistle (Onopordum acanthium, tauricum) 

Spotted knapweed (Centaurea stoebe) 

Sulfur cinquefoil (Potentilla recta) 

Tamarisk/Salt Cedar (Tamarix ramosissima) 

Wild caraway (Carum carvi) 

Yellow toadflax (Linaria vulgaris) 

List “C” Species

Cheatgrass/Downy brome (Bromus tectorum)  

Common mullein (Verbascum thapsus)         

Field bindweed (Convolvulus arvensis)