Douglas County

Conservation District

 Noxious Weeds offer little food value for wildlife and livestock.  They out compete and crowd out native and more desirable plants.  Some are toxic to animals and humans.  They reduce crop production and reduce land values.  They increase soil erosion and the loss of precious topsoil.   This site is to educate landowners about these weeds to first identify them then work on preventing them from spreading.  The following are some species that are currently on either the A, B, or C List of the Colorado Noxious Weed Act

 

Noxious Weeds List A Species

Myrtle Spurge Euphorbia mysinites (A)

· Erect, square stem can be smooth to hairy, multi-branched and 1 1/2 to 8 feet tall

· Leaves are lance-shaped, entire and whorled

· Magenta-colored flowers gave 5 to 7 petals arranged in long racemes

 

Purple Loosestrife Lythrum salicaria(A)

Helping People Help the Land ~ Colorado

 List A Species (18 species-list below)

All populations of List A species in Colorado are designated by the Commissioner for eradication.  It is a violation of these rules to allow any plant of any population of any List A species to produce seed or develop other reproductive propagules.  Prescribed management techniques must be applied to every population of List A noxious weeds present in Colorado to achieve the following objectives:

* The plants of every population of List A species must be eliminated prior to seed development

* Once all mature plants are eliminated, appropriate efforts must be made to detect and eliminated new plants arising from seed, reproductive propagule, or stock for the duration of the seed longevity for the particular species.

* In order to ensure that seeds or other reproductive propagules are not produced or spread, any plant with flowers, seeds, or other reproductive propagules mus be placed in sealed plastic bags and disposed of.

The above is a small segment from the Colorado Noxious Weed Act.   To view the complete Colorado Noxious Weed Act, go to www.ag.state.co.us/CSD/weeds/statutes/weedrules.pdf                A few species below on List A.

 

 

· Flowers are bright yellow with distinctive spines at the base.

· Forms pea-green rosettes that quickly turn silvery-green as they become full grown plants.

· The stems are winged and can be up to two feet long.

· Each plant produces thousands of seed

Yellow starthistle covers millions of acres in the west but it has only been found in a handful of locations within Colorado.  It is critical that this plant be eliminated wherever it is found.

Yellow Starthistle

Cirsium  ochrocentrum (A)

·  Highly aggressive invader species which can be found in riparian areas, rivers and lakes.

· Each plant can produces up to 3 million seeds.

· Poses a severe threat to waterfowl habitat and can impede water low in irrigation ditches.