Member of the mint family identified?

They spread underground. The flowers are tiny and are spotted inside. It's always been clear that they're a member of the mint family, because of the square stems. They were here when we arrived. In such great masses, they do have a faint smell when in bloom, but otherwise not. Somebody told me that they were betony, but that never seemed right. Someone else thought they were one of the skullcap family. Now it appears that they may be sweet germander (wood sage? teucrium canadense). Whatever they are, the bees have always loved them.