Asclepias incarnata (swamp milkweed) is an Ontario native plant/milkweed that is essential for the survival of the Monarch butterfly. The Monarch butterfly larvae lay their eggs on Asclepias incarnata and the larvae emerge to feed on the leaves. In full sun Asclepias incarnata flowers for many months followed by decorative, green seed pods. It emerges from winter dormancy very late. Be patient. It begins to grow with warmer weather.