I was out tromping around in our wildflower meadows this morning & look what I spied!
Eastern Black Swallowtail cats!!
There were several of them of this size that I saw. Here's a photo of another one:
I had to shade it with my hat in order to get the photo.
I have wondered for a long time what this plant was & tried researching before but it was darn hard to figure it out. With the new information of knowing it's the host for BST's I was able to nail it down and have now added photos and data details (as much as I could find) to our db.