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
Squarrose Knapweed
Centaurea virgata
Adult Squarrose knapweed is a native plant of the eastern Mediterranean area. It is very competitive on rangelands. Knapweed releases a chemical substance reducing competing vegetation. This long-lived perennial grows 12 to 18 inches tall. |
Rosette The rosette and stems have deeply lobed leaves. |
Flower Flowers are rose to pink. It is often confused with diffuse knapweed, but differs in that the toothed flower bracts are curved outward, and are not laterally toothed. Bloom occurs in early to mid-summer. |