Watch List

The Colorado Watch List pdf file consists of 22 species that have been determined to pose a potential threat to the agricultural productivity and environmental values of the lands of the state and require careful observation. Many species included on this list are not yet known to occur in the state but have been recognized as noxious or problematic by another state or states in the region. For the included species that do occur in Colorado, more information is needed about the distribution and effect on agricultural and natural lands in the state.

If you find a population of one of the Watch List species, please fill out the Spotter Form.

 

Watch List Species

Asian mustard © Lara Hartley 

Asian mustard 
Brassica tournefortii

 

Babys Breath © Richard Old 

Baby's breath
Gypsophila paniculata

 

Spiny_cocklebur_005 © John Randall 

Bathurst burr/
Spiney cocklebur

Xanthium spinosum

 

Brazilian_elodea_005 

Brazilian Elodea
Egeria densa

Common bugloss © J.S. Peterson  

Common bugloss
Anchusa officinalis

 

Common reed © Leslie Mehroff 

Common reed
Phragmites australis

 

Flowering rush © Louis Landry 

Flowering rush
Butomus umbellatus

 

Garlic mustard 

Garlic mustard 
Alliaria petiolata

Hairy willow-herb © Richard Old 

Hairy willow-herb 
Epilobium hirsutum

 

Himalayan blackberry © John Randall 

Himalayan blackberry 
Rubus armeniacus

 

Congongrass © Charles Bryson USDA 

Japanese blood grass/
cogongrass
  
Imperata cylindrical

 

Meadow hawkweed © Richard Old 

Meadow hawkweed 
Hieracium caespitosum

Onionweed © William Ciesla

Onionweed 
Asphodelus fistulosus

 

Parrotfeather_005

Parrotfeather 
Myriophyllum aquaticum

 

 Purple pampasgrass © John DiTomaso 

Purple Pampasgrass 
Cortideria jubata

 

Scotch broom © Eric Coombs

Scotch broom 
Cytisus scoparius

Sericea lespedeza © Dan Tenaglia  

Sericea lespedeza
Lespedeza cuneata

 

Swainsonpea © Richard Old 

Swainsonpea 
Sphaerophysa salsula

 

Syrian beancaper © Dell Clark 

Syrian beancaper 
Zygophyllum fabago

 

Water hyacinth © Chris Evans 

Water hyacinth 
Eichhornia crassipes

Water lettuce © Richard Old 

Water lettuce 
Pistia stratiotes

 

White bryony © Jan Samanek 

White bryony 
Bryonia alba

 

Whoolly distaff thistle © Joseph DiTomaso 

Woolly distaff thistle 
Carthamus lanatus

 

Yellow flag iris © Patty York 

Yellow flag iris 
Iris pseudacorus

Yellow_floatingheart_005 

Yellow floatingheart 
Nymphoides peltata

 

Yellowtuft_005 

Yellowtuft 
Alyssum murale & A. corsicum