Bistorta affinis (synonyms Polygonum affine, Persicaria affinis), the Himalayan bistort, fleece flower, or knotweed, is a species of flowering plant in the family Polygonaceae, native to the Himalayas (Tibet, Nepal, northern India, Pakistan, Kashmir).
(D. Don) Greene
Bistorta affinis is a creeping, densely tufted, mat-forming perennial, growing to 25 cm (10 in) tall by 60 cm (24 in) broad. The narrow elliptic leaves are white on the underside because of a waxy coating. Leaves are mostly at the base, 3–8 cm long, with the base narrowed to a short stalk. Leaf margins are entire or very finely toothed. The mid-vein is prominent. Cylindrical spikes of many pale pink or rose-red flowers are borne at the top of short erect stems, from midsummer to autumn. Flower-spikes are 5–7.5 cm (2–3 in) long, with densely crowded flowers. Stamens protrude slightly out of the flowers. Flowering stems are several, 5–25 cm tall, with very few smaller leaves. When the flowers have died, they tend to persist on the plant into winter.
Bistorta affinis is found in the Himalayas, from Afghanistan to eastern Nepal, at altitudes of 3,000–4,800 m (9,843–15,748 ft).
- "Bistorta affinis (D.Don) Greene". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-03-01.
- "BSBI List 2007". Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-01-25. Retrieved 2014-10-17.
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
- Flora of China, Polygonum affine D. Don, 1825. 密穗拳参 mi sui quan shen
- "Kew Gardens - Plants & fungi - Persicaria affinis". Archived from the original on 25 May 2013. Retrieved 25 May 2013.
- Pink, A. (2004). Gardening for the Million. Project Gutenberg Literary Archive Foundation.
- "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 75. Retrieved 22 April 2018.
- "RHS Plant Selector - Persicaria affinis 'Darjeeling Red'". Retrieved 25 May 2013.
- "RHS Plant Selector - Persicaria affinis 'Donald Lowndes'". Retrieved 25 May 2013.
- "RHS Plant Selector - Persicaria affinis 'Superba'". Retrieved 25 May 2013.