Teucrium aroanum .....Or is it Teucrium aroanium?
I'd hoped to harvest seed from this, but the flower heads I processed yielded 19 seeds, perhaps enough for two or three packets. I'm going to sow them myself and see what happens. If they grow, the seedlings will have some small degree of genetic diversity and perhaps seed set will be better.
Harvesting those 19 seeds was a matter of putting the crushed flower heads through a coarse sieve, then examining the effluent with a hand lens and picking out the individual seeds on the end of a toothpick.
It's a very tough plant, btw.