Bistorta affinis or also known as Polygonum affine, Fleece Flower, Lesser Knotweed, East Indian Knotweed, Himalayan Bistort, Knotweed. It is a native plant to Tibet, Himalaya. It is in the genus Bistorta, from the Polygonaceae family of plants.
The leaves are narrow and elliptic. The leaves are lighter, almost whitish underneath. The middle vein is very prominent. The leaves turn reddish-bronze in autumn. Bistorta affinis blooms in summer. It flowers with spikes of pale rose flowers on erect stems. The spikes are cylindrical and about 3in or 7.5cm long.
It is a mat-forming perennial that loves the sun or could grow in partial shade. Easy to care for, it grows to about 25cm or 10in. It produces pink flowers from July to September. Propagate by seed or division. It is generally disease-free and pest-free.