Mark it would help if there were some foliage shown or even the whole plant. There's Chrysanthemum catananche but the white parts of that should be closer to cream I think and then there are two or three Leucanthemum forms or hybrids which have that slightly murky pink ring around the disc. There's a hybrid between Rhodanthemum mawii and something else which is matlike rather than bushy like its parent, and so on.
