Centaurea calcitrapa (weed)
Centaurea calcitrapa (weed) L. - (purple starthistle)
This plant is native to Europe and western Asia but has become established in several parts of North America. It reproduces only by seeds (Pitcairn et al., 2002).
For details see the respective page in Wikipedia.
Publications covering Centaurea calcitrapa (weed)
Biological Invasions (2019) 21, 99-110
Daniel Montesinos, Ryan C. Graebner and Ragan M. Callaway (2019)
Evidence for evolution of increased competitive ability for invasive Centaurea solstitialis, but not for naturalized C. calcitrapa
Weed Technology (2002) 16, 452-456
Michael J. Pitcairn, James A. Young, Charlie D. Clements and Joe Balciunas (2002)
Purple starthistle (Centaurea calcitrapa) seed germination