Butterfly weed usually refers to Asclepias tuberosa, and often to other Asclepias (milkweeds.) Butterfly bush is usually used to refer to Buddleia but often used in regard to Lantana as well. Common names are fine for walking around the yard, but proper names or pics are necessary to discuss plants when not there in person.
thanks for your answers! flowAjen, your answers were superb, as I know nothing! I followed your links and could see what I am growing! I bought 3 bare root butterfly bushes but there was no choice of color so it will be a surprise when they bloom. They are only about 5 inches tall now. Maybe I will see more action next year.
I also bought a package of orange butterfly weed seeds because I like the orange.