Perhaps my favorite native perennial is Asclepias tuberosa. In summer it's covered with tiny, beautiful bright orange blossoms, and is a magnet to butterflies. Hence the common name, butterfly weed. It grows in part sun in the worst clay soil on the property without any care. This year I was delighted to see it attracted a butterfly I'd never seen before - the zebra swallowtail.
To see other interesting creatures, check out the Friday Creature Feature at Garden Adventures.