Flachblatt-Mannstreu

Usually the title of my Flower Friday entries is not in German. But I did like this name so much. Mannstreu (man-loyal), a plant?
In English this plant is called blue eryngo or flat sea holly. (I have also seen the name Garden See Thorn. In Latin it is an Eryngium planum.
In folk medicine the plant is amongst others used to help you pee.
Thanks to BikerBear for hosting the FF challenge.