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This perennial forms mats that creep over rocks and steep slopes in the central Himalaya. The fresh green leaves emerge in spring and the flower spikes develop in late summer, bearing numerous, small pink or red flowers. After the first frosts, the leaves turn red then chestnut-brown.

[KSP]

Kew Species Profiles

General Description
This mat-forming perennial with smooth leaves and spikes of small pink or red flowers was once admired in the Himalaya by Sir Joseph Hooker, one of Kew's early directors.

This perennial forms mats that creep over rocks and steep slopes in the central Himalaya. The fresh green leaves emerge in spring and the flower spikes develop in late summer, bearing numerous, small pink or red flowers. After the first frosts, the leaves turn red then chestnut-brown.

One of Kew's early directors, Sir Joseph Hooker, admired this species in the Himalaya, and described it 'hanging in rosy clumps from moist precipices'.

Species Profile
Geography and distribution

Native to the region from Afghanistan to Nepal and India and also in China (Tibet) at elevations up to 4,900 m.

Description

A creeping perennial that can form mats several metres across. The leaves are smooth, lanceolate or narrowly elliptic, bluish on the undersides and 3-8 cm long. The flowering stems are 5-25 cm long, with sheathing leaves at the base and dense flower spikes 5.0-7.5 cm long. The flowers are pale pink to red, five lobed and 4-6 mm across. Each flower has eight stamens and three styles. The fruit is a three-angled nutlet.

Uses

Persicaria affinis is cultivated as an ornamental and is widely available from commercial nurseries under this name or the synonym Polygonum affine . Cultivars include P. affinis 'Superba' (with red and pale pink flowers) and 'Donald Lowndes' (with pale to dark pink flowers). Both have received an Award of Garden Merit from the Royal Horticultural Society.

In the Garhwal Himalaya the flowers of knot weed are used as a stimulant, and in the Ladakh region of Jammu and Kashmir an extract of the root is used in traditional medicine against fever.

This species at Kew

Knot weed can be seen growing in the Woodland Garden surrounding the Temple of Aeolus, and in the Plant Family Beds at Kew. It can also be found in the Himalayan Glade at Wakehurst; these specimens were brought back and planted by Tony Schilling, who was Curator at Wakehurst between 1967 and 1991.

Distribution
China, India
Ecology
Rocky mountainsides, screes, glacial moraines, alpine pastures, wet meadows and river banks.
Conservation
Not evaluated according to IUCN Red List criteria.
Hazards

Apparently distasteful to grazing animals.

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[KSP]
Use
Ornamental, traditional medicine.

Native to:

Afghanistan, East Himalaya, Nepal, Pakistan, Tibet, West Himalaya

English
Knot weed

Bistorta affinis (D.Don) Greene appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jan 1, 1988 Strachey, R. [s.n.], Uttaranchal K000831196
Jan 1, 1988 Edgeworth, M.P. [14], Uttaranchal K000831193
Jan 1, 1988 Wallich, N. [1692], Tibet K000831194
Jan 1, 1988 Wallich, N. [1692], Uttaranchal K000831195
Jan 1, 1988 Blinkworth, R. [1692], Uttaranchal K000831197
Jan 1, 1988 Madden, E. [s.n.], Uttaranchal K000831191
Jan 1, 1988 s.coll. [1692], Tibet K000831192
Gerard, P. [Cat. no. 1683], India Polygonum affine K001113850
Wallich, N. [Cat. no. 1683], Nepal Polygonum affine K001113848
Wallich, N. [Cat. no. 1683], Nepal Polygonum affine K001113851
Blinkworth, R. [Cat. no. 1683], India Polygonum affine K001113849

First published in Leafl. Bot. Observ. Crit. 1: 21 (1904)

Accepted by

  • Qaiser, M. (2001). Flora of Pakistan 205: 1-190. Department of Botany, University of Karachi, Karachi.
  • Grierson, A.J.C. & Long, D.G. (1983). Flora of Bhutan 1(1): 1-186. Royal Botanic Gardens, Edinburgh.

Not accepted by

  • Akeroyd, J.R. (2013). Docks and Knotweeds of Britain and Ireland: 1-258. Botanical Society of Britain and Ireland. [Cited as Persicaria affinis.]
  • Govaerts, R. (2001). World Checklist of Seed Plants Database in ACCESS E-F: 1-50919. [Cited as Persicaria affinis.]

Literature

Kew Species Profiles

  • The Plant List (2010). Persicaria affinis.
  • Lancaster, R. (1995). A Plantsman in Nepal. Antique Collectors’ Club, Woodbridge, Suffolk.
  • Navchoo, I.A. & Buth, G.M. (1992). Ethnobotany of Ladakh – J. & K. State. In: Ethnobotany in India (Journal of Economic. Taxonomi. Botany. Additional. Series 10), eds J. K. Maheshwari, G. Kunkel, M. M. Bhandari & J. A. Duke, pp. 251-258. Scientific Publishers, Jodhpur.
  • Tandon, A., Verma, D.L. & Khetwal, K.S. (1991). Flavone C-glycosides from the inflorescence of Polygonum affine. Fitoterapia 62: 185.
  • Polunin, O. & Stainton, A. (1984). Flowers of the Himalaya. Oxford University Press, New Delhi.
  • Lloyd, P.S. & Lloyd, S. (1968). A study of the autecology of Polygonum affine D. Don in the Karakoram Mountains. Journal of Ecology 56: 723-738.
  • Hooker, J.D. (1880). Polygonum affine. Curtis’s Botanical Magazine. 106: tab. 6472.

Kew Backbone Distributions

  • Wu, Z. & Raven, P.H. (eds.) (2003). Flora of China 5: 1-505. Science Press (Beijing) & Missouri Botanical Garden Press (St. Louis).
  • Grierson, A.J.C. & Long, D.G. (1983). Flora of Bhutan 1(1): 1-186. Royal Botanic Gardens, Edinburgh.
  • Rechinger, K.H. & Schiman-Czeika, H. (1968). Flora Iranica 56: 1-88. Akademische Druck- u. Verlagsanstalt, Graz.

Herbarium Catalogue Specimens
'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
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Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Science Photographs
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Species Profiles
Kew Species Profiles
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