Allium christophil, the wandering stars of the July garden here. They started life at the furthest edge of my garden but once the seedheads dry they roll elsewhere in the wind and now grow in a large swathe at the opposite end of the flower garden. Thankfuly even the weather of summer 2012 has done nothing to prevent their beauty and they are much appreciated not only by mere humans but also by visiting Bees and Hoverflies. There's a little Hover hidden within one version which you might enjoy trying to find.
These flowers grow from bulbs, reach a height of between 15 and 40 cm (6-16 ins) and have a large, spherical umbel of 50 or more star-shaped, purplish-violet flowers. All forms of ornamental Allium are cousins to the Onions you use in your dinner!