Asclepias incarnata, Swamp Milkweed - this beautiful perennial can get to be up to 5 feet tall. It can grow in a range of soil conditions but prefers full sun and moist to wet conditions. Its pink flows bloom July through September attracting a wide range of pollinators, and of course its a host to Monarch Butterfly caterpillars.
 
Native throughout most of NC. Click to see its range in North Carolina.

More info here