A worldwide community photographing and learning about wildlife
Papilio troilus
The Black Swallowtail has a black spot at the center of the orange dot on the upperside base of the hind wing. The real clincher, though is the row of orange spots on the underside. Black Swallowtails have an uninterrupted row of orange spots. If you look at your last two images, you see two orange spots near the lower middle portion of the underside of the hind wing, followed by a whitish-blue streak, followed by more orange spots. That is always indicative of Spicebush Swallowtail.
Here is a website that has photos to compare the dorsal (topside) and ventrao (underside) views of all the dark swallowtails. http://louisiananaturalist.blogspot.com/...
The way I tell is the extent of the blue coloration on the hind wing. The spicebush the light blue covers about half of the hind wing. The black swallowtail has one row of blue and a row of yellow on top of that on the hind wing. Sorry if I'm not explaining well, if you google images for both species you should be able to see what I'm trying to explain.
What distinguishes a spicebush from a black? I thought the wing shape looked more like the black swallowtail?