HerbWildPerennialMedicinal

Persicaria barbata (L.)H.Hara

Bearded knotweed

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Description

Persicaria barbata is an annual to short-lived perennial herb, usually 30–120 cm tall, growing erect or ascending. Stems are slender, cylindrical, often branched, and sometimes reddish, with swollen nodes characteristic of the Polygonaceae family. Leaves are simple, alternate, and lanceolate to narrowly elliptic, usually 5–20 cm long and 1–4 cm wide. Leaf margins are entire, apex acute, and surfaces are generally glabrous. The leaf base forms a characteristic ochrea, a membranous sheath surrounding the stem at each node. Ochrea margins are often fringed with hairs. Flowers are small, bisexual, and pink to reddish, arranged in terminal or axillary spike-like racemes. The perianth consists of 4–5 tepals, usually petaloid. Stamens are 5–8, and the ovary is superior with a branched style. Fruits are small triangular achenes, dark brown to black at maturity, enclosed within persistent perianth segments.

Diagnostic Characters

Vegetative

Swollen stem nodes. Ochrea present at nodes. Narrow lanceolate leaves.

Floral

Pink spike-like inflorescences. Small clustered flowers.

Fruit & Seed

Three-sided blackish achene.

Distribution

Native range: Tropical and subtropical Asia.

In Pakistan: Found in Pakistan, India, Bangladesh, Southeast Asia. Common in humid regions and along water bodies.

Phenology

Flowering

Fruiting

Flowering: Summer–autumn Fruiting: Autumn

Ethnobotany & Uses

Medicinal Importance

Traditionally used for Digestive disorders, Inflammation, Skin problems. Plant extracts contain Flavonoids, Phenolic compounds.

Ecological Importance

Provides habitat for insects. Important component of wetland vegetation.

Agricultural Importance

May occur as a weed in Rice fields, Irrigated crops.

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Where it grows on campus

This species is on the campus floristic list but was not pinned during the GPS mapping survey, so it has no map records yet.

Taxonomic Notes

Persicaria was formerly included within Polygonum. Molecular studies have separated several wetland knotweeds into Persicaria.