A biennial herb of European origin with pink flowers on prickly stems. It is established across most of North America and is regarded as a noxious weed nearly everywhere.
- Centaurea biebersteinii, family Compositae
More example sentences
- The weeds, spotted knapweed and leafy spurge, are native to Europe.
- The spotted knapweed is a European invader that, over the last hundred years, has spread throughout the pastures and rangeland of western North America, often out-competing native species.
- Sheep are efficient foragers and, unlike cattle, can thrive on a fair number of invasive weeds, such as leafy spurge and spotted knapweed.