Motherwort, Leonurus cardiaca
Anybody who says there are no straight lines in nature (I say/said it all the time!) have not seen the flower stem of Motherwort. It is long, straight and completely and utterly square.
Easy to grow, Motherwort is a perennial crown herb that likes to be in part shade and doesn’t really need much water, but really it’s very tolerant of all conditions like all good mothers. After flowering it does tend to fling its spikey seeds around. The seedlings are easy to pull out, or better yet it’s at it’s optimum time to harvest when it’s flowering.