Robuta

https://www.rhs.org.uk/plants/3370/centaurea-scabiosa-greater-knapweed-black-top/details Centaurea scabiosa | greater knapweed Herbaceous Perennial/RHS centaurea scabiosa greater knapweed herbaceous perennial rhs https://www.rhs.org.uk/plants/131725/centaurea-scabiosa-f-albiflora/details Centaurea scabiosa f. albiflora | /RHS centaurea scabiosa f rhs