Arrowleaf Knotweed
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Arrowleaf Knotweed
A Native Photo: Rajkumari Supriya Devi
Common name: Arrowleaf Knotweed, American tearthumb, Arrowleaf tearthumb, Arrow-vine • Manipuri: ꯢꯁꯤꯡ ꯂꯤꯜꯍꯔ Eshing Lilhar
Botanical name: Persicaria sagittata    Family: Polygonaceae (Knotweed family)
Synonyms: Polygonum sagittatum, Truellum sagittatum, Tracaulon sagittatum

Arrowleaf Knotweed is a slender annual herb 1-2 m long, reclining on other plants, or erect when young, the stems 4-angled, reflexed-prickly as are usually also the leaf-stalks and flower-cluster-stalks and the midrib beneath the leaves. Leaves are sometimes velvet-hairy on margins, lanceshaped to elliptic, 2-10 cm, to 2.5 cm wide, arrow shaped at base, the lobes directed downwards. Flowers borne in a short, head-like cluster, long-stalked at branch-ends and in leaf-axils. It is seldom over 1 cm; flowers pink to white or green; style 1.5 mm, trifid to the middle. Seedpods are trigonous, 2.2-3 mm. Arrowleaf Knotweed is found in marshes and wet meadows, Siberia to Himalaya and Temperate E. Asia, Central & E. Canada to Central & E. U.S.A., Hispaniola. In the Himalayas it is found at altitudes of 100-2200 m. Flowering:
Medicinal uses: The plant has been used with success in the treatment of nephritic colic, relieving the pains caused by gravel. The plant contains a small amount of anthraquinone derivatives. It has long been used in Indonesian traditional medicine to treat diarrhea, skin diseases, and internal problems.

Identification credit: Rajkumari Supriya Devi Photographed in Manipur.

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