Eryngium amethystinum syn. Eryngium dilatatum

Must try, striking amethyst colouring. "Like many garrigue plants adapted to heat and drought, (this) is able to tolerate abundant rain and occasional periods of severe cold"

Amethyst Sea Holly is both hardy and architectural Mediterranean plant.  It's known for its striking unusually colored amethyst, tall flower heads, surrounded by silvery bracts, and its spiny, leathery, much divided  leaves. The plant flowers in mid to late summer and provides winter interest with its spikey seed heads. At only 30-50cm it's great for the front of a border.  Perfect in shingle and recommended by Olivier Filippi, in his Mediterranean garden books. I have visited his garden and was so impressed! Loved by pollinators.   

From Morocco, Portugal and Spain

Not many, but some seed. 

Quote by Olivier Filippi.