August's weed of the month is Puncturevine (Tribulus terrestris)
Why is it a Noxious Weed?
How would I identify it?
Where does it grow?
In Oregon Noxious weeds fit into classifications;
A weed of known economic importance which occurs in the state in small enough infestations to make eradication or containment possible; or is not known to occur, but its presence in neighboring states make future occurrence in Oregon seem imminent. Recommended action: infestations are subject to eradication or intensive control when and where found.
A listed Weed:
B listed Weed:
A weed of economic importance which is regionally abundant, but which may have limited distribution in some counties. Recommended action: Limited to intensive control at the state, county or regional level as determined on a site specific, case-by-case basis. Where implementation of a fully integrated statewide management plan is not feasible, biological control (when available) shall be the primary control method.
T Designated Weed:
A designated group of weed species that are selected and will be the focus for prevention and control by the Noxious Weed Control Program. Action against these weeds will receive priority. T-designated noxious weeds are determined by the Oregon State Weed Board and directs Oregon Department of Agriculture (ODA) to develop and implement a statewide management plan. T-designated noxious weeds are species selected from either the A or B list.
How do I control it?
Merle Keys, Wasco County Weed Department Supervisor
2705 E. 2nd Street
The Dalles, OR 97058
Phone (541) 506-2653
For more information see the resource pages linked below or contact the Wasco County Weed Department
Photo credit Google search: flickr.com
photo from Eastern Washington University
photo from flickr.com Google search
Resources for this page from:
Oregon Department of Agriculture Noxious Weed Control Program
Invasive Spotted Knapweed Spreading - Steinbachonline.com
Noxious Weeds Blog
Spotted Knapweed – June 2017 Weed of the Month – Noxious Weeds Blog
Puncturevine is a native of the southern Europe and Mediterranean region. This noxious weed was first discovered in gravel along railroad tracks in Whitman County, Washington in 1924. Puncturevine has rapidly spread throughout the Northwest mainly through human activity by sticking in car tires, footwear and onto animals.
Puncturevine is a warm-season annual which grows horizontal along the ground. Single plants form dense mats up to six feet across. Leaves are divided into 4 to 8 pairs of leaflets. The weed has small yellow flowers with 5 petals. The fruits consist of a woody bur that splits when mature into a very sharp spike like tack with rigid spines. A single plant can produce around 400 fruit each containing two or three seeds.
This noxious weed can be found in Eastern, Southeastern and Central Oregon , and increasing in counties in the Willamette Valley. This plant can be found in gravel parking lots, along roadways, irrigated vegetable crops and in heavily used locations by livestock that are known to spread the seed.
The best method of control is to prevent establishment by destroying the first plants once found before burs begin to form. Puncturevine can be pulled and is recommended to put the plant in its entirety into a barrel and burned.There are also several biocontrol agents that are known to have a positive affect on controlling this noxious weed. Contact your local weed department for more information or the Oregon Department of Agriculture for tips to control and prevent the spread of puncturevine.