I have a horse tail problem and every year this little purple flower comes up and I leave it, but now I'm wondering if it is related to the horse tails and I should get rid of it? It grows basically right in/next to a little swampy water area. On a side note, let me know if you know how to get rid of horse tails without killing everything! That would really be awesome to get rid of them. At any rate, let me know if you know what this purple flower thingamajiggy is. I attached two pictures of it and a couple of the horse tails I'm battling everywhere. Thanks for any advice!!