Lysimachia clethroides
Lysimachia clethroides, better known as gooseneck loosestrife, is described in one plant catalog as “vigorous to the point of invasiveness.” That’s actually a little bit of an understatement. At our old house we had this and St. John’s wort growing together just outside our front gate. Cathy thought it would be interesting to see which would do better. I was constantly pulling this up to give good old St. John a fighting chance. We have it in a few places in out new yard. Cathy actually dug some up this year, not to replant it but to make room for something else. It doesn’t like to share its space and will basically choke out anything and everything else. But it does have these elegant little flower spikes.