Asclepias incarnata, Rose Milkweed, is also commonly called Red Milkweed, Marsh Milkweed, or Swamp Milkweed.
That lovely vanilla fragrance you detect coming from large rosy pink flowers possibly hosting several Monarch or Swallowtail butterflies is Rose Milkweed. This deer-resistant plant grows best in moist but will tolerate average soils, and blooms for about a month mid-summer. Later, large pods form which will break open to reveal seeds that will float away in the wind. Large numbers of Rose Milkweed can often be seen growing in wetland settings.