Diffuse knapweed
About This Species
Diffuse knapweed plants can produce up to 18,000 seeds per year that can remain dormant in the soil for a long time. Seeds can be spread by wind, livestock, and people. Diffuse knapweed is often found growing open areas and well-drained soils where they establish in grasslands, open forests, and along roadsides – it is uncommon on cultivated land. They choke out desirable forage for livestock and wildlife and increase soil erosion.
How to Identify
Fine-textured Diffuse knapweed has hairy, greyish-green, split leaves on many branches growing from a single upright stem. The flowers are white or sometimes purple, with small, sharp, rigid spines on the bracts. Diffuse knapweed grows to 0.1 to 0.6 m. flowers are white, sometimes rose-purple or lavender, broadly urn-shaped, found in clusters or solitary at the end of branches. Bracts are yellowish with a brownish margin, sometimes spotted, fringed on the sides, and terminating in a slender bristle or spine. It has larger, hairy leaves at the base of the plant that get smaller as they go up the stem. Seeds are light brown to black in colour.
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Knapweeds Factsheet -
If you need advice about invasive species on your property or you are concerned about reported invasives in your local area, contact your local government or regional invasive species organization.
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Diffuse knapweed is a PlantWise "Alert" species - Gardeners should avoid purchasing or planting.
