No Cornflower?

I have a flower that looks like a cornflower but it's bigger and it is purple(lilac). It is about 1.5' high and the flower is about 4" wide and is shaped like a ball. When it was growing it looked like a tulip (before it bloomed). Any suggestions?

No Cornflower?
I'll give it a try...





Stokesia (stoke's aster)


http://images.search.yahoo.com/search/im...





Allium (ornamental onion)


http://images.search.yahoo.com/search/im...
Reply:Cornflower photo:


http://www.herbdatanz.com/CornflowerA.gi...





Centauria photo:


http://i.pbase.com/u45/mattis/upload/293...
Reply:Is it centauria? That looks lilke a cornflower only bigger, it is a relative.
Reply:Purple Allium
Reply:That might be in the campanula family -- a balloon flower, maybe?
Reply:hydranga?