Washoe Valley Noxious

What Are Those Weeds? ...and what to do about them. Click on "More information" for a UNR Cooperative Extension Weed Wanted Poster with more information including how to eradicate these weeds. Some weeds have the official designation "Noxious Weed" and get special eradication attention. "Obnoxious Weed" is washoevalley.org's designation for those other pesky weeds we find in our yards. The weeds below are just a few of the ones attacking Washoe Valley. See these links for more: UNR Cooperative Extension Wanted Posters
Credits: UNR Cooperative Extension except where noted.
click on the each photo for a larger one
Tall whitetop, or perennial pepperweed, is a native of southern Europe and western Asia. It has naturalized in many parts of the United States, including Nevada. Many western states have declared it a noxious weed. This perennial grows in waste places, wet areas, ditches, roadsides, and croplands, including alfalfa fields. It is a problem in hay bales because it does not cure. The robust, spreading roots and numerous seeds make control difficult to impossible. Mechanical measures such as disking or mowing spread the plant. Chemical control treatments must be timed properly and applied only after last season’s debris is removed or the effort is wasted. Tall whitetop is listed as a noxious weed by Nevada Administrative Code.	Tall Whitetop More Information (pdf)
Puncturevine an annual, forms a mat 1 to 10 feet in diameter. Introduced from southern Europe, it has spread throughout the United States in waste areas, along roads, and in pastures and fields. The seeds are found in hard, spiny burs that can penetrate skin, bicycle tires, and even sidewalls of auto tires. These spiny burs are harmful to livestock, are objectionable in hay, and reduce the quality of wool fleece. Yellow flower appears from July to October. The spiny bur develops shortly afterwards. Puncturevine is a noxious weed by the Nevada Administrative Code.	Puncturevine More Information (pdf)
Yellow starthistle is a Mediterranean weed that dominates rangelands, roadsides, and fields primarily in Oregon, Washington, California, and Idaho. It is found scattered throughout the rest of the U.S. In Nevada, it can dominate rangeland that receives less than 15 inches of annual precipitation. It completely changes the natural habitat it invades. The injurious nature of its vicious spines negatively impacts recreationists, livestock, and wildlife. It is poisonous to horses, causing a nervous disorder called “chewing disease” when they are forced to eat it. Yellow starthistle is listed as a noxious weed by Nevada Administrative Code.	Yellow starthistle More Information (pdf)
Bur Buttercup, an "Obnoxious Weed" is invading bare areas all over Washoe Valley (2006). This weed will produce a dry bur which will stick your dogs feet, tangle in their hair and stick you when you try to remove it. Bur buttercup (Ranunculus testiculatus) is an exotic annual weed, native of southeastern Europe that has become widespread in gardens, small grains, pastures, wastes areas, and along roadsides in the western USA. It is a winter annual that emerges, flowers, and sets fruits in the spring, when temperatures climb into the 45 to 50-degree range. It is a toxic species because it contains ranunculin, a chemical that changes into to protoanemonin, a highly toxic compound. The transformation of ranunculin into protoanemonin occurs when the plant is crushed. There are reports of sheep poisoning after ingesting bur buttercup. Source It is important to control bur buttercup before they produce flowers and seeds. Hoeing, pulling and digging can control bur buttercup. So early, early spring is the time to get these guys. More info on bur buttercup and other winter annual weeds.	Bur Buttercup More Information
More weeds will be added soon. Have a weed you want identified? Send in a clear photo.