About Bistorta affinis (D.Don) Greene
Bistorta affinis (D.Don) Greene is a creeping, densely tufted, mat-forming perennial plant. It grows up to 25 cm (10 in) tall and spreads to 60 cm (24 in) wide. Its narrow elliptic leaves have a white underside caused by a waxy coating. Most leaves grow at the base of the plant, are 3–8 cm long, and narrow at the base to form a short stalk. Leaf margins are either entire or very finely toothed, and the mid-vein is prominent. From midsummer to autumn, cylindrical spikes of many pale pink or rose-red flowers grow at the tops of short, erect stems. These flower spikes are 5–7.5 cm (2–3 in) long, with densely packed flowers. The stamens of each flower protrude slightly beyond the petals. This species produces multiple flowering stems that are 5–25 cm tall and bear only a very few smaller leaves. After flowering, dead flower spikes typically remain on the plant through winter. Bistorta affinis is native to the Himalayas, occurring between Afghanistan and eastern Nepal at altitudes ranging from 3,000–4,800 m (9,843–15,748 ft). It is cultivated as an ornamental groundcover. Under its older scientific synonym Persicaria affinis, three cultivars have received the Royal Horticultural Society's Award of Garden Merit: 'Darjeeling Red', 'Donald Lowndes', and 'Superba'.
