Land Plants - invasive

Spotted Knapweed (Centaurea stoebe ssp. micranthos) on Aug 8, 2008

Submitter has sample

Description of specimen

purple flowering knapweeds that match pictures set out by the forest service, as invasive species that should be reported. They are at least 3 feet tall, and most definitely seeding all over the place. There are too many to personally pull.

Commentary

Dear Chloe,

Thanks for your report of knapweed. I am guessing you are referring to spotted knapweed since that species is very abundant in Deschutes County. Is that right?

Knapweed is an incredibly invasive species known to displace native vegetation, ruin wildlife habitat, and decrease the value of land. I will forward this report to the county weed guy (Dan Sherwin), but unfortunately they are already so abundant in that area that it is unlikely it will be targeted for control unless it is threatening a habitat or property of value. Dan will probably notify the land owners and encourage them to control it.

Private land owners are responsible for controlling weeds on their property, but sometimes people don’t do anything because the task seems too daunting or they are unaware of how much harm it can cause. The silver lining to this gloomy picture is citizen stewardship. There are many dedicated volunteers who join forces to uncover and protect their favorite areas from knapweed and other aggressive invaders. One example is that Deschutes County has an annual weed pull called Let’s Pull Together. This year they pulled literally one ton of knapweed from the Bend area. Maybe you were there? In some cases, the SWCD can help coordinate the effort and provide resources.

We hope you will keep on reporting! By looking for and reporting some of the less abundant, but equally as aggressive, invasive species, we can control them before they become tomorrow’s spotted knapweed. The priority weeds for control in Deschutes county are listed below. I would encourage you to familiarize yourself with these invaders and report them if you see them.

Thanks again and keep on reporting!

Tania Siemens
OSU Sea Grant/The Nature Conservancy
tania.siemens@oregonstate.edu


Priority weeds in Deschutes County

Hawkweeds Hieracium sp.
Purple Loosestrife Lythrum salicaria
Leafy Spurge Euphorbia esula
Yellow toadflax Linaria vulgaris
Whitetop Hoary Cress Cardaria draba
Yellow Star thistle Centaurea solistialis
Ribbon Grass Phalaris arundinacea var. picta
Perennial Pepperweed Lepidium latifolium
Medusahead Rye Taeniatherum caput-medusae

Tania Siemens
Aug. 27, 2008, 12:53 a.m.