Greater Knapweed - Centaurea scabies is big and showy, like a cross between a cornflower and a thistle, with whiskery petals in a whorl. It is a valuable nectar source for insects and a favourite flower of butterflies, including the Marbled White and Dark Green Fritillary. It also has therapeutic properties, and was once used in skin ointments to heal wounds and infections. Centaurea scabiosa is a truly outstanding wild flower which outshines many cultivated plants.
Site has suggestions for plants/flowers that will attract and provide food for bees in all 4 seasons (click photo)... nice - and informative Journal article, click link here - http://www.jstor.org/stable/2455613?seq=1#page_scan_tab_contents. More