Saltcedar
Tamarix ramosissima Ledeb.
Shrub or small tree5 to 20 ft
A shrub with scale like leaves and pink to white flowers. Also called tamarisk.
Acroptilon repens L.
Russian Knapweed
Identification
Russian Knapweed
Acroptilon repens L.
- Life cycle
- Perennial
- Height
- Up to 3 ft
Russian knapweed is a grayish perennial up to 3 feet tall that usually grows in dense clumps. Leaves are alternate and of several types. The upper leaves are small, narrow and smooth edged. Stem leaves are larger with small toothed margins, and basal leaves are deeply notched.
Stems branch profusely, with flowers at the ends. Flowers are thistle like, lavender, with a scaly seed head. Roots are very dark and heavily scaled. Seeds are flattened and ivory in color, held in cup shaped seed heads.
Control
Controlling russian knapweed
- Best timing
- Picloram applied after several hard frosts, around mid October, has given nearly 100 percent control the next spring.
- Mowing and pulling
- Mowing and cultivation alone do not control it. In cropland, cultivation combined with herbicide suppresses it. Livestock generally will not graze it.
- Herbicide
- Picloram (Tordon) is one of the most effective. Metsulfuron (Escort) and aminopyralid (Milestone) are also options.
- Biological control
- A gall fly released in 2009 is established. A gall wasp has had little impact.
Always follow the product label, and check rates in the North Dakota Weed Control Guide from NDSU. Your county weed control officer can tell you what fits your land. Source: NDSU Extension W1411 (December 2025).
Keep Looking
Other weeds on the state list
Yellow Toadflax
Linaria vulgaris
Perennial12 to 24 in
Yellow flowers with an orange, bearded throat that look like small snapdragons.
Spotted Knapweed
Centaurea maculosa Lam.
Biennial or short lived perennial1 to 3 ft
Pinkish purple flowers with dark fringed bracts. Takes hold fast on disturbed ground.
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