U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
|Surprise Field Office|
Russian Knapweed (Acroptilon repens)
Description: Perennial forming dense colonies by shoots from widely spreading black roots. Stems erect, openly branched, up to 3 feet. Lower leaves deeply, but not so finely, divided; upper leaves entire or serrate. Flowers 1/4 to 1/2 inch in diameter, numerous on the ends of branches. Ray flowers pink to lavender. Phyllaries pearly, rounded or pointed, with papery margins. Seeds small, from 1/8 to 1/4 inck long, with numerous whitish bristles.
Distribution: Russian knapweed is the most widely distributed knapweed in northern California. One of the lagest infestations in an 80 acre site east of Bieber in Big Valley (Lassen County).