Tropical Milkweed is a host plant for Monarch butterflies. The red and yellow flowers provide a much loved nectar source for butterflies and hummingbirds. Plant it in fertile, moist soil for best results. Hardy to 15F, it should return for you in zones 8b-11. Elsewhere treat it as an annual. It self-seeds a bit for us here in zone 7B.
Photo courtesy of Bud Hensley