🏯Khmer Traditional Medicine

Swamp Herb (Bok Khleng)

Polygonum tomentosum

About Swamp Herb (Bok Khleng)

Swamp Herb (Bok Khleng) (Polygonum tomentosum) is a herb used in the Khmer Traditional Medicine tradition to help with Wound Healing, Fever, Digestive Issues, and Skin Health, among 1 other condition it addresses. The leaves are the part traditionally used, used both internally and topically.

Botanical background

Persicaria lapathifolia (syn. Polygonum lapathifolium), known as pale persicaria, is a plant of the family Polygonaceae. It is closely related to Persicaria maculosa and as such is considered a weed in Britain and Europe. Other common names for the plant include pale smartweed, curlytop knotweed, and willow weed. It is a species complex made up of a great many varying forms, sometimes considered varieties. The environment also has a strong influence on the morphology of an...

Source: Wikipedia, via iNaturalist

Parts used

Leaves · both
🍵

Tea / Infusion

1–3 cups daily
  • Steep 1–2 tsp of dried Swamp Herb (Bok Khleng) in freshly boiled water for 5–10 minutes.
  • Cover while steeping.
  • Strain and drink.
💧

Tincture

20–40 drops in water, 2–3× daily
  • Pack dried Swamp Herb (Bok Khleng) into a jar and cover with 40–60% alcohol.
  • Seal and steep for 4–6 weeks, shaking daily.
  • Strain and store in a dark dropper bottle.
💊

Powder / Capsule

500 mg – 1 g, 1–3× daily
  • Grind dried Swamp Herb (Bok Khleng) into a fine powder.
  • Fill size 00 capsules or stir into smoothies or honey.
🖐️

Topical / Poultice

1–2× daily as needed
  • Mash fresh Swamp Herb (Bok Khleng) or mix the powder with a little water to form a paste.
  • Apply to the affected area for 20–30 minutes.
🫙

Infused Oil

Massage into affected area 1–2× daily
  • Fill a jar with dried Swamp Herb (Bok Khleng).
  • Pour over a carrier oil until submerged.
  • Leave for 4–6 weeks, then strain.
  • Use topically or as a salve base.
🛁

Herbal Bath

2–3× per week as needed
  • Brew 4–6 tbsp of Swamp Herb (Bok Khleng) in 1 litre of hot water for 15 minutes, strain, and add to a warm bath.
  • Soak for 20–30 minutes.

Pregnancy, Breastfeeding & Children

No herb-specific pregnancy/child safety research is documented for Swamp Herb (Bok Khleng) in our references — the guidance below is based on its general effect category, not research on Swamp Herb (Bok Khleng) itself. Always confirm with a midwife, doctor, or pediatrician.

Pregnancy

Insufficient Data

No specific pregnancy safety research is documented for this herb in our references. This doesn't mean it's unsafe — it means it hasn't been well studied. Treat as unstudied and avoid unless a midwife or doctor familiar with your pregnancy advises otherwise.

Breastfeeding

Insufficient Data

No specific breastfeeding safety research is documented for this herb in our references. Treat as unstudied and consult a lactation consultant, midwife, or doctor before use.

Children

Insufficient Data

No specific pediatric safety/dosage research is documented for this herb in our references. Treat as unstudied and consult a pediatrician or pediatric herbalist before giving to a child.

Contraindications

    Warnings

    ⚠️ Allergic Reactions

    Discontinue immediately if you experience rash, itching, swelling, or difficulty breathing.

    ⚠️ Not Medical Advice

    This information is for educational purposes only. Always consult a qualified healthcare provider before using herbal remedies.

    Drug & herb interactions

    No specific drug or herb interactions are documented for Swamp Herb (Bok Khleng) in our references. This doesn’t mean none exist — always check with a pharmacist or doctor before combining any new herb with prescription medication.

    Where to find in nature

    Native region

    Various global regions

    Climate

    Varied

    Habitat

    Cultivated in traditional medicinal gardens, botanical gardens, and herb farms worldwide

    🌿 To see Swamp Herb (Bok Khleng) growing, visit botanical gardens, university plant collections, or specialist herb nurseries near you. If foraging in the wild, always work with an expert identifier — never consume a plant you are not 100% certain of.

    Where to buy

    In store

    • Health food stores (Whole Foods, Natural Grocers, Holland & Barrett, GNC)
    • Naturopathic clinics and integrative medicine practices
    • Specialist herbal apothecaries and herbalist practices
    • Farmers markets with herb vendors

    Online

    iHerb

    Wide selection of standardised extracts, capsules, and powders with lab testing

    Mountain Rose Herbs

    Premium bulk dried herbs — certified organic, ethically sourced

    Starwest Botanicals

    Large selection of certified organic bulk herbs and powders

    Herb Pharm

    High-quality liquid extracts and tinctures, rigorous quality standards

    Amazon

    Convenient — verify brand certifications and check third-party testing

    Etsy

    Small-batch artisan herbalists, hand-harvested and wildcrafted herbs

    Quality tips

    When buying Swamp Herb (Bok Khleng), look for: certified organic labelling, clearly stated country of origin, third-party lab testing for heavy metals and pesticides, and a batch expiry date. Standardised extracts offer consistent dosing; bulk dried herbs are more economical for regular use. Avoid very cheap, unlabelled products — quality varies enormously.