I love cardoons (Cynara cardunculus) throughout the summer, but when the purple thistle-like flowers open on top of the globes, they are truly wonderful. The bees and butterflies love them too. The large silver foliage makes this an impressive border plant, but it needs a bit of space as it gets tall and eventually about 4' wide (this one is fairly young).

The plant was introduced to Britain in the 1600's and has been popular in stately, and not so stately, gardens ever since. 

An edible plant, the stems are apparently delicious blanched in late summer, although we have not tried it.