Here's a somewhat different look at this butterfly. The spreadwing shot is typical, because of the way these guys perch. Here, I was fortunate to be able to shoot from the side, though foliage did get in the way in one photo. Ironically, every spreadwing shot I took that day didn't turn out.

I think the plant being visited was deerweed. It proved popular with several other species of butterflies and a huge (bumble?) bee.