Eryngium or sea holly? If it is then you can find out what exact species it is by googling for pictures and pick out the one you want. There are several.

Gotta be Eryngium of some variety, with blueish purple stems. The other one with steely blue thistle like flower heads is Echinops ritro, but the stems are green.

And in my garden is a swine to propagate. I've got 4 different eryngiums but have tried to grow echinops 4 times without a glimmer of germination, either direct planted or from a pot.

OOer, odd - mine's got huge, masses of flowers this year, but every year the foliage succumbs to capsid attack...