Cang Er Cao苍耳草
Xanthii Herba · Cocklebur Herb · Siberian Cocklebur Aerial Parts
Overview
· Disperse Wind-Cold — to Cang Er Zi 苍耳子. Cang Er Cao is the stem and leaf of Xanthium sibiricum, the same plant that yields Cang Er Zi. It is not a smaller version of the fruit: the aerial part is bitter and acrid but slightly cold, and it is used for wind-damp painful obstruction and for skin disease — sores, scabies, ringworm and stubborn itching — rather than for the nose. It is toxic, and the toxicity is of a different order from the mild warning attached to most herbs in this chapter, so the entry below is written as a record of classical use, not as something to try.
Nature & Flavor
Bitter, acrid · Slightly cold · Slightly toxicChannels
Lung · Spleen · LiverTypical Dosage
6–15 gActions
3 core actions
- Dispels wind and dampWind-damp painful obstruction with aching, stiff joints and cramping of the limbs.
- Clears heat, resolves toxicityBoils, sores and swellings; used both internally and as a wash.
- Kills parasites, stops itchingScabies, ringworm, eczema and persistent itching — chiefly as an external wash, which is the safer of its two routes.
In Formulas
Formulas containing Cang Er Cao
No published formula lists this herb yet — the library is growing.
Indications & Clinical Uses
- Wind-damp painful obstruction with joint ache and limb cramping
- Sores, boils and toxic swellings
- Scabies, ringworm, eczema and stubborn itching (mainly external)
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Toxic — this herb causes liver injury in overdose. The whole cocklebur plant is toxic, and the young seedlings and cotyledons most of all. The toxic principles are the atractyloside-type glycosides (carboxyatractyloside,); serious poisoning and deaths have been recorded, most often from people eating the young shoots as a wild vegetable, and less often from raw or excessive medicinal use.
Never eat the seedlings, and never self-treat with the raw plant. Internal use belongs inside a prescription, within the stated range, using properly identified and prepared material — not foraged plants.
Signs of poisoning — nausea, vomiting, abdominal pain, marked fatigue, drowsiness, jaundice, deranged liver enzymes — require the herb to be stopped and urgent medical care. Anyone with existing liver disease should not take it internally at all.
Prefer the external route where the indication allows it; the wash carries far less risk than the decoction.
Contraindicated in pregnancy: Contraindicated in pregnancy and while breastfeeding. It is a toxic, hepatotoxic herb with no margin that would justify its use at either time.
For licensed practitioners’ reference only
References
- Ben Cao Gang Mu《本草纲目》(Ming dynasty, public domain).
2. 《中华本草》— Xanthium sibiricum, aerial parts: toxicology and recorded poisoning.
3. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
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.