I don't know what I was thinking when I picked this name many years ago, but I believe what you have there is a Lycopus sp.

Err it does look like that....Lycopus, get out of her flower beds ;)

Ok...now wait a minute...if you're not too agressive you can stay....but if you stay you might grow a little tired of my incessant "what is this?"'s :)

Could you narrow down the species? I looked it up and it seemed that the only terribly aggressive species was Lycopus europaeus....in fact some Lycopi (not sure how to write the plural ;) are listed as threatened. I don't have flower beds or a garden....just some land that I'm trying to restore, so, "weeds" as long as they're not terribly aggressive are generally welcome!