Click for information on Mosquito Control

Contact Info

Phone: 307-472-5559
Hours: 7:30am - 4:00 Monday-Friday
If you need assistance after hours: Please Call Brian Connely , 307-267-3848

Weed Facts and Terminology

Invasive species are the second leading cause of animal decline and extinction, worldwide!!!

Noxious weeds are a major threat to western rangeland and wildlife. It is estimated that 5000 acres of western lands are being invaded by noxious weeds every day! These invaders must be stopped! Only through concerted effort by public land managers, land owners, and citizens can we accomplish this.

What is a “noxious weed”?

Legally the term is used to describe any plant of exotic origin that harms agriculture, commerce, wildlife, navigation or native ecosystems. Noxious weeds originate from other continents and are accidently (or
sometimes even purposefully) released into our environment. Many of these plants have invasive and aggressive adaptations that allow them to compete with our native plant communities. In their native range they are kept in check by complex set of biotic and abiotic factors such as predators, insects, and climate. However, when these factors are not present in our native ecosystem the noxious weed is left unchecked.

Why do they become such a problem?

Instead of a complex and diverse native plant community, noxious weeds have the ability to create a dense homogenous stand, or “monoculture”. By invading and changing the native plant community, noxious weeds disrupt the web of life and adversely affect the community of animals that rely on them, including humans. Their adverse affects include: loss of hunting and fishing opportunities, reduced wildlife and landscape viewing opportunities, reduced agriculture potential, higher food prices, etc.

Celestine Lacey Duncan’s “A Literature Review of Ecological and Economic Impact of Noxious Weeds” provided the following information:
~Spotted knapweed invasion of bunchgrass sites in western Montana results in a 200-300% decline in winter elk forage (Bedunah and Carpenter, 1989)
~Impacts on leafy spurge on wildlife habitat were studied in Theodore Roosevelt National Park from 1992-1993. It was found that use of grazing areas by mule deer was reduced 70% by infestations of leafy spurge.
~Purple loosestrife reduces desirable waterfowl plants such as cattails that are preferred habitats for muskrats and long-billed marsh wrens (Rawinski and Malecki, 1984). Waterfowl broods are also more susceptible to predation because dense stands of purple loosestrife reduce access from water to nesting sites.
~Small mammal populations have been reduced as Russian knapweed displaces native species (Kurz, 1995).

TERMINOLOGY

Allelopathic: A plant that produces a chemical substance that affects adjacent plants’ ability to grow or thrive

Alternate: Leaves that grow up the stem on alternate sides

Annual: A plant that grows, produces seed, and dies in one growing season

Biennial: A plant which lives 2 years, usually grows as a rosette the first season and then produces seeds and dies at the end of the second growing season

Bract: Small leaf-like structure below the flower

Clasping: Blade of the leaf extending wholly or partly around the stem

Cordate: Heart-shaped

Deciduous: Leaves falling at the end of the season

Declared weed: A weed on a county list that has been determined to be detrimental. In Natrona County declared weeds may be subject to a cost share in chemical purchases for treatment.

Designated weed: Weeds on the Wyoming State Designated noxious weed list that have been determined by the Wyoming Weed and Pest Council and the Department of Agriculture to be detrimental.InĀ  Natrona County designated weed are subject to a cost share.

Integrated Weed Management (IWM): Using a combination of methods to control weeds including education, prevention, mechanical, cultural, biological, and chemical control.

Lanceolate: Lance-shaped

Leaflet: One small blade of a compound leaf

Lobed: Cut into shallow segments

Noxious weed: Legal term used to describe plants of exotic origin that can interfere with ecology, agriculture, navigation, fish or wildlife, or public health. (Does not necessarily mean it is poisonous!!!)

Perennial: A plant that lives more than 2 years

Prostrate: Lying against the ground

Pubescent: Covered with hairs

Raceme: Arrangement of flowers along a stem on the individual stalks about equal in length

Rhizomatous: Having rhizomes

Rhizome: A stem growing under or along the ground which sends out new shoots to develop new plants

Rosette: Compact cluster of leaves often arranged in a basal circle

Weed: General term used to describe any plant that inteferes with management objectives of the land user (May be a native plant.)