Appendages of lower involucral bracts are lacerate, like
in one of the parents,
C. jacea. Appendages of middle and upper involucral bracts
are pectinate, like in the other parent, C. nigra. As this is a species of hybrid origin, there is plenty
of variation, so that it's hard to find two plants that are
are exactly alike. It turns out the hybrid knapweed has become very
widespread, at least across the Tidmarsh farms territory. It is much more common
there than even the invasive spotted knapweed.