CLASS A WEEDS
Black Henbane
Diffuse Knapweed
Johnsongrass
Leafy Spurge
Medusahead
Oxeye Daisy
Purple Loosestrife
St. Johnswort
Spotted Knapweed
Sufur Cinquefoil
Yellow Starthistle
Yellow Toadflax
CLASS B WEEDS
Bermudagrass
Dalmatian Toadflax
Dyer's Woad
Hoary Cress
Musk Thistle
Perennial Pepperweed
Poison Hemlock
Russian Knapweed
Scotch Thistle
Squarrose Knapweed
CLASS C WEEDS
Canada Thistle
Field Bindweed
Houndstongue
Quackgrass
Saltcedar
Black Henbane
Diffuse Knapweed
Johnsongrass
Leafy Spurge
Medusahead
Oxeye Daisy
Purple Loosestrife
St. Johnswort
Spotted Knapweed
Sufur Cinquefoil
Yellow Starthistle
Yellow Toadflax
CLASS B WEEDS
Bermudagrass
Dalmatian Toadflax
Dyer's Woad
Hoary Cress
Musk Thistle
Perennial Pepperweed
Poison Hemlock
Russian Knapweed
Scotch Thistle
Squarrose Knapweed
CLASS C WEEDS
Canada Thistle
Field Bindweed
Houndstongue
Quackgrass
Saltcedar
Russian Knapweed
Centaurea repens
Adult A perennial, Russian knapweed grows two to three feet tall. |
Rosette Basal leaves are lobed and are two to four inches in length. |
Weed Infestation Russian knapweed is native to Eurasia. It infests rangelands, field edges, pasture, roadsides, and other disturbed soils. Knapweed's release chemical substances into the soil that inhibit the growth of competing vegetation. It can cause "Chewing disease" in horses that consume it. |
Flower It has pinkish flowers. Bloom is early summer through late summer. |
Tap Root  Roots are black and may go eight feet deep or more. |
Flower Bract Flower bracts have membranous cream-colored tips. |