??????

I found this plant yesterday and have no idea what it is. I haven't found it in any of my books and haven't been able to identify it on wildflower websites.

I have never seen this one before. It was growing in a ditch, sandy, rocky soil and very moist at the edge of the woodline. It's blooms, about dime size, are a very pale lavender color. The plants were all in one group and were from 12" to 24" tall. Notice the leaves are always in 3s with long stem in between leaves. I have a friend who is researching trying to help identify it.