There are lots of exciting species of Asclepias in the U.S.A. This is one of the most common and deserves to be more widely grown over here. The flowers, in contrasting pale and dark pink resemble those of a Hoya (to which it is related) and are worth a close look. Leafy, clump-forming herbaceous perennials with reddish stems to 2ft. Any soil, but heavy and damp soils in sun are especially favoured.
3L pots ~ £8