The lists of Colorado's Noxious Weeds are located in the below table. 

• To view the differences in listing species click on the list below (either A, B, or C) and the answer will drop down, click again to close the answer
• To view more about a specific weed click on the name in blue text. If a plant name does not have a link this is because a plant plan or assessment has not been completed.
• To view pictures go to theNoxious Weed Image page

• List A species

  List A species in Colorado that are designated by the Commissioner for eradication.

• List B species

  List B weed species are species for which the Commissioner, in consultation with the state noxious weed advisory committee, local governments, and other interested parties, develops and implements state noxious weed management plans designed to stop the continued spread of these species.

• List C species

  List C weed species are species for which the Commissioner, in consultation with the state noxious weed advisory committee, local governments, and other interested parties, will develop and implement state noxious weed management plans designed to support the efforts of local governing bodies to facilitate more effective integrated weed management on private and public lands. The goal of such plans will not be to stop the continued spread of these species but to provide additional education, research, and biological control resources to jurisdictions that choose to require management of List C species.

• Watch List species

  Watch List weed species that have been determined to pose a potential threat to the agricultural productivity and environmental values of the lands of the state. The Watch List is intended to serve advisory and educational purposes only. Its purpose is to encourage the identification and reporting of these species to the Commissioner in order to facilitate the collection of information to assist the Commissioner in determining which species should be designated as noxious weeds. The Watch List

To sort the information click the column header you want to sort by.

Common Name	Scientific Name	List (Classification)
African rue	Peganum harmala	List A
Bohemian knotweed	Polygonum x bohemicum	List A
Camelthorn	Alhagi pseudalhagi	List A
Common crupina	Crupina vulgaris	List A
Cypress spurge	Euphorbia cyparissias	List A
Dyer's woad	Isatis tinctoria	List A
Elongated mustard	Brassica elongata	List A
Giant knotweed	Polygonum sachalinense	List A
Giant reed	Arundo donax	List A
Giant salvinia	Salvinia molesta	List A
Hydrilla	Hydrilla verticillata	List A
Japanese knotweed	Polygonum cuspidatum	List A
Meadow knapweed	Centaurea pratensis	List A
Mediterranean sage	Salvia aethiopis	List A
Medusahead	Taeniatherum caput-medusae	List A
Myrtle spurge	Euphorbia myrsinites	List A
Orange hawkweed	Hieracium aurantiacum	List A
Purple loosestrife	Lythrum salicaria	List A
Rush skeletonweed	Chondrilla juncea	List A
Squarrose knapweed	Centaurea virgata	List A
Tansy ragwort	Senecio jacobaea	List A
Yellow starthistle	Centaurea solstitialis	List A
Absinth wormwood	Artemisia absinthium	List B
Black henbane	Hyoscyamus niger	List B
Bouncingbet	Saponaria officinalis	List B
Bull thistle	Cirsium vulgare	List B
Canada thistle	Cirsium arvense	List B
Chinese clematis	Clematis orientalis	List B
Common tansy	Tanacetum vulgare	List B
Common teasel	Dipsacus fullonum	List B
Corn chamomile	Anthemis arvensis	List B
Cutleaf teasel	Dipsacus laciniatus	List B
Dalmatian toadflax- broad leaved	Linaria dalmatica	List B
Dalmatian toadflax- narrow leaved	Linaria genistifolia	List B
Dame's rocket	Hesperis matronalis	List B
Diffuse knapweed	Centaurea diffusa	List B
Eurasian watermilfoil	Myriophyllum spicatum	List B
Hoary cress	Cardaria draba	List B
Houndstongue	Cynoglossum officinale	List B
Leafy spurge	Euphorbia esula	List B
Mayweed chamomile	Anthemis cotula	List B
Moth mullein	Verbascum blattaria	List B
Musk thistle	Carduus nutans	List B
Oxeye daisy	Chrysanthemum leucanthemum	List B
Perennial pepperweed	Lepidium latifolium	List B
Plumeless thistle	Carduus acanthoides	List B
Quackgrass	Elytrigia repens	List B
Russian knapweed	Acroptilon repens	List B
Russian-olive	Elaeagnus angustifolia	List B
Salt cedar	Tamarix chinensis, T. parviflora, and T. ramosissima	List B
Scentless chamomile	Matricaria perforata	List B
Scotch thistle	Onopordum acanthium	List B
Scotch thistle	Onoporfum tauricum	List B
Spotted knapweed	Centaurea maculosa	List B
Spurred anoda	Anoda cristata	List B
Sulfur cinquefoil	Potentilla recta	List B
Venice mallow	Hibiscus trionum	List B
Wild caraway	Carum carvi	List B
Yellow nutsedge	Cyperus esculentus	List B
Yellow toadflax	Linaria vulgaris	List B
Bulbous bluegrass	Poa bulbosa	List C
Chicory	Cichorium intybus	List C
Common burdock	Arctium minus	List C
Common mullein	Verbascum thapsus	List C
Common St. Johnswort	Hypericum perforatum	List C
Downy brome	Bromus tectorum	List C
Field bindweed	Convolvulus arvensis	List C
Halogeton	Halogeton glomeratus	List C
Johnsongrass	Sorghum halepense	List C
Jointed goatgrass	Aegilops cylindrica	List B
Perennial sowthistle	Sonchus arvensis	List C
Poison hemlock	Conium maculatum	List C
Puncturevine	Tribulus terrestris	List C
Redstem filaree	Erodium cicutarium	List C
Velvetleaf	Abutilon theophrasti	List C
Wild proso millet	Panicum miliaceum	List C
Asian mustard	Brassica tournefortii	Watch List
Baby's breath	Gypsophila paniculata	Watch List
Bathurst burr, Spiney cocklebur	Xanthium spinosum	Watch List
Common bugloss	Anchusa officinalis	Watch List
Common reed	Phragmites australis	Watch List
Flowering rush	Butomus umbellatus	Watch List
Hairy willow-herb	Epilobium hirsutum	Watch List
Himalayan blackberry	Rubus armeniacus	Watch List
Japanese blood grass/cogongrass	Imperata cylindrical	Watch List
Meadow hawkweed	Hieracium caespitosum	Watch List
Onionweed	Asphodelus fistulosus	Watch List
Pampas grass	Cortideria jubata	Watch List
Scotch broom	Cytisus scoparius	Watch List
Sericea lespedeza	Lespedeza cuneata	Watch List
Swainsonpea	Sphaerophysa salsula	Watch List
Syrian beancaper	Zygophyllum fabago	Watch List
Water hyacinth	Eichhornia crassipes	Watch List
Water lettuce	Pistia stratiotes	Watch List
White bryony	Bryonia alba	Watch List
Woolly distaff thistle	Carthamus lanatus	Watch List

 

Click here for more information on the Noxious Weed Program.

 

 

 

 

 

 

 

Colorado Department of Agriculture · 700 Kipling Street · Suite 4000 · Lakewood, CO 80215-8000 ·(303) 239-4100