Gen info
- Persicaria is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants  in the genus are commonly known as knotweeds or smartweeds. The distribution is cosmopolitan. (5)
- Persicaria attenuata is a species of flowering plant native to Australia and Asia. It typically grows in wet land or streams.
- Etymology: The genus name Persicaria derives from Latin, meaning "peace tree", probably referring to the similarity of the leaves to that of a peach. (The Latin word for peach is malum Persicum.) The specific epithet attenuata derives from Latin attenuatus, meaning "weak, meagre, reduced". (7)

Botany
• A robust hairy rhizomatous herb that grows up to 2 m in height, with branched stems. Stems creep from the base and root at the nodes, becoming hollow as they age. Leaves are simple and alternate, the ochrea cylindrical and up to about 4 cm long, the surface coarsely villous, and the apex having a fringe of bristles. Petiole is quite short, up to about 7 mm long; the blade is narrowly ovate, more-or-less falcate, with the base tapering evenly to the stem, while the tip is long and pointed; up to 25 cm long and 5 cm wide, pubescent, with prominent veins below.
Inflorescence is a panicle of 2 to 5 spike-like racemes. Flowers are tiny, bisexual, with a campanulate perianth, white or pink lobes, 5 - 8 stamens, and a superior ovary. Plant flowers for much of the year. Fruit is a lens-shaped nut, about 3 mm long, and brownish black in color, shiny, and with short spiny tips. (Some Magnetic Island Plants)

• Stout decumbent herb 60–100 cm high; stems glabrous or with very scattered long hairs; stalked glandular hairs sometimes present on stems, inflorescence branches and leaves. Leaves narrow-ovate, ± falcate, 8–20 cm long, 15–50 mm wide, variably pubescent, usually at least the margins and main veins with long white appressed hairs, lamina glabrous to subvillous, lower surface usually with sessile glands, less often glandular above; petiole 10–40 mm long; ocrea glabrous or sparsely hairy, with cilia 0–3 mm long. Spikes elongate-cylindrical, very dense, 4–11 cm long, 6–10 mm diam. Perianth segments 2.8–3.8 mm long, white. Achene lenticular, 2.0–2.5 mm long, 2.0–2.4 mm diam., dark brown to blackish.
(New South Wales Flora Online)

Distribution
- Native to the Philippines. (2)
- In Luzon: Laguna, NCR; Mindanao: Maguindanao del Sur, Zamboanga; Mindoro, Palawan, Panay. (2)
- Native to Lesser Sunda Is., New Guinea, New South Wales, Northern Territory, Queensland, South Australia, Victoria, Western Australia. (1)

Constituents
- No reports found specific for P. attenuata. Extracts of Persicaria plant have yielded phytochemicals suchs as polyphenols, tannins, polyuronides, flavonoids triterpenes, glycosides, saponins, and essential oils. (8)

Properties
- Studies have suggested anti-inflammatory, acetylcholinesterase inhibitory properties.

Parts used
Leaves, shoots.

Uses
Edibility
- Leaves are edible, raw or cooked; eaten in salads in Indo-China and Africa.
Folkloric
- No reported folkloric medicinal use in the Philippines.
- In Southeast Asia, leaves are eaten with food as a tonic and to purify the blood. (6)
- Vegetable salt from burnt plant applied to scrofulous sores. (6)
- Leaves used for treatment of syphilis, rheumatism, and swellings.
- Poultice of shoots and leaves applied to forehead to treat fever.
Others
- Agroforestry: Plant considered an indicator of land suitable for rice cultivation. (6)

Studies
• Anti-Inflammatory / Acetylcholinesterase Inhibitory / Leaves: Study evaluated methanolic extracts of seven Persicaria plant species for anti-inflammatory and inhibitory effects on enzymes involved in chronic inflammation viz., inhibition of nitric oxide production, acetylcholinesterase activity, and 15-lipoxygenase activity and quantity of M1/M2 cytokines release. At concentration of 50 µg/mL, P. attenuata showed 92.07% NO inhibition, and 66.55% cell viability in LPS-activated RAW 264.7 macrophages. On AChE inhibitory activity, six plants including P. attenuata showed moderate levels of inhibition, ranging from 33.51% to 56.93%, lower compared to eserine. (8)

Availability
- Wild-crafted.

Additional Sources and Suggested Readings
(1)
Persicaria attenuata / KEW: Plants of the World Online
(2)
Polygonaceae: Persicaria attenuata / Co's Digital Flora of the Philippines
(3)
Persicaria attenuata / Wikipedia
(4)
Persicaria attenuata / PROSEA: Plant Resources of Soouth-East Asia
(5)
Persicaria / Wikipedia
(6)
Persicaria attenuata / Ken Fern: Tropical Plants Database / Useful Tropical Plants
(7)
Persicaria attenuata / Some Magnetic Island Plants
(8)
Modulation of M1/M2 Cytokines and Inflammatory Enzymes by Persicaria Species Leaf Extracts in Lipopolysaccharide-stimulated RAW 264.7 Cell Macrophages / Adamu Imam Isa / Iranian Journal of Immunology, 2024; 21(3): pp 212-224

DOI: It is not uncommon for links on studies/sources to change. Copying and pasting the information on the search window or using the DOI (if available) will often redirect to the new link page. (Citing and Using a (DOI) Digital Object Identifier)