Spotted Knapweed (Centaurea stoebe ssp. micranthos) on Jul 7, 2025
Submitter does not have a specimen
EDRR Status: Local expert notified
Description of specimen
Perennial plant, 4 feet tall, with violet-purple flowers shaped somewhat like bachelor buttons (centaurea family)
Thank you for having a keen eye and concern for the natural resources in Polk County.
It is hard to tell if this is spotted or meadow knapweed from the picture. I'm leaning towards meadow knapweed, but I'd need help to confirm that. Both are invasive and deserve attention.
I will do some searching to determine who may have jurisdiction here. Thanks again for your report.
Chemical Control is advised unless it is a very small infestation.
https://pnwhandbooks.org/weed/problem-weeds/knapweeds-centaurea-spp-acroptilon-repens
Beth Thiel
July 8, 2025, 4:59 a.m.