Rhaponticum Species, Russian Knapweed, Russian Star Thistle, Turkestan Thistle

This plant is listed on the North Dakota invasive/troublesome list and this information is being distributed in a guide developed by the ...Read MoreND Weed Control Association and other agencies.

Plant Features
Perennial, up to 3 feet tall, forms patches
Bracts on flower head rounded, pale green, transparent tips
Flowers at the ends of leafy branches
Flowers purple to pink, cone-shaped, 1/2 inch wide
Small stiff hairs give plants a grayish look
Blooms June through September
Primarily spreads by large dark brown to black, bark-like creeping (rhizomatous) roots
Roots may reach depths up to 20 feet

Distribution
Documented in a few areas. Grows under most conditions including salilne and alkaline soils

Interesting Facts
Flowers resemble the garden flower bachelor buttons
Irritates skin, poisonous to horses
Suppresses growth of other plants by releasing a toxin (allelopathic).
Widespread invasive in western U.S.

Russian Knapweed, Turkestan Thistle, Russian Star Thistle, Acroptilon repens, is a naturalized plant in Texas and other States and is con...Read Moresidered an invasive plant in Texas.

Culture:
Grow in any soil, concrete, or rock. Treat with a mixture of Glyphosphate (roundup) and 2-4D. The plant must be spraye...Read Mored when it is getting leafy (when it is 4" tall, any more and it can recover rapidly) and continued to be sprayed untli all of the roots are dead. This is the only plant that survives when subdivisions are buils and soil is cleared- the still come up, even through asphalt. But, with persistnence and water (which makes it grow better but weaker in competition with other plants) it is possible to eradicate it.

If you are an organic no-pesticide sort of person, I suggest you gain a taste for it in your favorite poisonous salad- I'm, afraid that it cannot be controlled without sprays.

This is the THE least wanted noxious weed in Montana. It seed readily and cannot be pulled. prevents other plants from growing near its...Read More base. BAD PLANT!