Persicaria alpina, or Alpine Knotweed is a semi-evergreen, clump forming perennial that has large, lance-shaped, mid-green foliage.
In summer it produces showy plumes of small creamy-white flowers on tall stems that are followed by pinkish-red seed heads.
They go well in the middle or as a background to mixed borders, while also making a good low screen or hedge.
They are also suitable for informal garden styles and in smaller courtyard gardens as a feature.