Shui Ding Xiang水丁香
Herba Ludwigiae Prostratae · Water Primrose · Ludwigia Herb · Willow Primrose
Overview
The whole aerial plant of Ludwigia, a yellow-flowered marsh herb of the evening-primrose family that grows in ditches and paddy margins across southern China and Taiwan. It belongs to the regional folk pharmacopoeia rather than the classical materia medica: bitter and cold, it is taken as a decoction to clear heat, resolve toxin and drain damp downward, and is used locally for feverish colds, hot diarrhoea and dysentery, urinary heat and swelling, and — externally as well as internally — for boils and infected sores. Names for it vary by region, so identity should be confirmed with the supplier before use.
Nature & Flavor
Bitter · ColdChannels
Lung · Large Intestine · BladderTypical Dosage
9–18 g of the dried herb in decoction; fresh plant mashed for topical useActions
4 core actions
- Clears heat, resolves toxinFeverish colds with sore throat, and hot painful sores and boils — internally as a decoction and externally as a poultice of the fresh plant.
- Drains damp, promotes urinationScanty, hot, painful urination and puffy swelling with a damp-heat picture.
- Cools the intestinesDiarrhoea and dysentery-type stools with urgency, burning and mucus, in the damp-heat pattern.
- A regional folk herbWell established in Taiwanese and southern Chinese folk use but absent from the Chinese Pharmacopoeia, with limited modern safety data; treat dose and duration conservatively.
In Formulas
Formulas containing Shui Ding Xiang
No published formula lists this herb yet — the library is growing.
Indications & Clinical Uses
- Feverish colds with sore throat
- Damp-heat diarrhoea and dysentery-type stools
- Hot, scanty, painful urination and damp-heat swelling
- Boils and infected sores, internally and as a topical poultice
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Clearly cold and draining: it is not for a cold, weak Spleen, for chronic loose stools, or for anyone frail and depleted, and it is meant for short courses during an acute episode rather than continuous use. Because it is a folk herb rather than a pharmacopoeial one, it has little published safety, interaction or quality-control data — confirm the botanical identity with the supplier, since several plants share this common name regionally, and do not combine it with prescription medicines without telling both practitioners. Persistent fever, bloody stools or urinary symptoms need medical assessment rather than a longer course of herbs.
Contraindicated in pregnancy: Safety in pregnancy has not been established for this folk herb — avoid it in pregnancy unless a practitioner has specifically indicated it.
For licensed practitioners’ reference only
References
- 《中华本草》 (modern comprehensive materia medica).
2. Taiwanese and southern Chinese folk materia medica; not listed in 《中华人民共和国药典》.
3. Draft entry describing regional usage; pending practitioner review.
Professional reference notice. Entries are scholarly references for licensed TCM practitioners and students — not medical advice, and not a recommendation to self-prescribe. Chinese herbal formulas should be used under the guidance of a qualified practitioner. Content is an original editorial compilation by Cura x Cura, cross-checked against the cited references.