I'll have to admit, over the years I've picked up a lot of little botanical odds and ends that I'm not completely sure I know the identity of and often I don't quite know what to do with them (though calling my garden Fibber Mcgee's closet, as one garden visitor did, I feel is a little bit of an exaggeration... if the reader is young, you'll probably have no idea why somebody would compare my garden to a closet in the first place). Anyway, this is one of my oddments... it carries a fading label that identifies it as "Dracocephalum arguense". It obviously should be spelled argunense, but I'm not sure that would be any closer to the truth, as the foliage of that species is rather leathery and needle-like, from what I can gather, whereas my plant has rather delicate light green leaves.
It certainly is a dracocephalum, an interesting little genus of so-called "dragonheads" from Europe and Asia. My plant is about eight inches tall and forms a loose clump; it's that awkward size that's too big for a rock garden plant, but too small and delicate to hold up in a border.
I'm a sucker for lavender blue flowers, so it's in no danger of being ousted, but it has to make do with a little spot of sun in front of an azalea... not much respect for a dragon.