|
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 B Species |
|
Canada thistle Cirsium arvense (B) |
|
Dalmation toadflax Linaria dalmatica (B) |
|
Helping People Help the Land ~ Colorado |
|
This escaped ornamental is beginning to show up in our wildlands. This native of Europe may be either a biennial or perennial, and may be from 1-1/2 to 4 feet tall, flowers range in color from white to pink to purple. Dame’s Rocket flowers from April through July. This plant tends to invade riparian and wetland habitat. There are many alternatives to planting Dame’s Rocket including Blue Columbine (Aquilegia caerulea) and Lavender Native Bee Balm (Monarda fistulosa menthaefolia). |
|
Dames Rocket Hesperis matronalis (B) |
|
List B Species (39 species-list below) List B noxious 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 B Species must be managed in accordance with all the provisions of this Part 4, including any applicable state noxious weed management plans. Until a plan for a particular species is developed and implemented by rule, all persons are recommended to mange that species. * The plants of every population of List B species designated for eradication must be eliminated prior to seed development in the year specified. * Any population that is discovered in areas designated for eradication subsequent to the year specified for elimination must be eliminated prior to the development of viable seed. If the population is discovered after seed development has occurred, then efforts must be made to minimize the dispersion of seed and elimination is required prior to seed development in the following year. * Once all plants are eliminated, appropriate efforts must be made in subsequent years to detect and eliminate new plants arising from seed, reproductive propagule, or root stock prior to seed development 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 must 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 B.
|
|
Diffuse Knapweed Centaurea diffusa (B) |
|
Canada thistle is a creeping perennial that reproduces from vegetative buds in its root system and from seed. It is difficult to control because its extensive root system allows it to recover from control attempts. Combining control methods is the best form of Canada thistle management. Persistence is imperative so the weed is continually stressed, forcing it to exhaust root nutrient stores and eventually die.
|
|
Houndstongue Cynoglossum officinale (B) |
|
A biennial introduced from Europe and member of the borage family. It reproduces by seeds and appears as a leafy rosette the first year. The stem is erect, stout, heavy, 1-1/2 to 3 feet high, usually branched above. The upper leaves are narrower and pointed, almost clasping. The flowers are terminal and reddish-purple in color. The fruit consists of four nutlets (seeds), each about 1/3 inch long, with the outer surface covered with short, barbed prickles. Seeds break apart and are rapidly scattered by animals. Houndstongue grows in ranges, pastures, and roadsides and is toxic to horses and cattle. The weed contains alkaloids that may cause liver cells to stop reproducing.
|
|
Leafy Spurge Euphorbia esula (B)
|
|
The waxy leaves are dark green with a light green midrib and mostly white margins The large and showy flowers are terminal, flat, nodding, upto 2-1/2 inches across, purple, rarely white, and surrounded by numerous, lance-shaped, spine-tipped bracts. Blooms appear in late May and June and set seed in June or July Musk thistle is commonly found in pastures, roadsides, and waste places. It prefers moist, bottom land soil, but can be found on drier uplands, . It is becoming an increasing problem throughout Colorado, particularly along the Front Range. |
|
Carduus mutans (B) |
|
Redstem filaree Erodium cicutarium (B) |
|
Yellow Toadflax Linaria vulgaris (B) |
|
Yellow and orange snapdragon-like flowers Slender leaves Perennial Adventitious buds on the roots form independent plants
|