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Cura x Cura

Zi Cao紫草

Arnebiae Radix · Arnebia Root · Gromwell Root · Zicao

Herbs that Clear Heat 清热药《神农本草经》

Overview

The dried root of arnebia and related borage-family plants, deep violet inside and staining everything it touches — the colour is the clue to how it is used. Sweet, salty and cold, it works at the blood level of the Heart and Liver to cool heat, resolve toxin and coax a stalled rash to the surface. It is equally at home outside the body: simmered into oil or ointment it gives the familiar purple, one of the oldest dressings for burns, weeping eczema and sores that will not close. The same cold, slippery quality that suits a febrile illness makes it a poor fit for a weak, cold digestion.

Nature & Flavor

Sweet, salty · Cold

Channels

Heart · Liver

Typical Dosage

5–10 g in decoction
紫草Photography for this entry is on its way.

Actions

4 core actions

  • Cools the blood, resolves toxinBlood-level heat showing as dusky purple macules rather than a bright red rash, toxic swelling of the throat, and the blotchy eruptions that accompany febrile illness.
  • Vents rashesMeasles and similar eruptive illnesses in which the rash surfaces incompletely or sinks back inward; traditionally given in small amounts during outbreaks as well as once the eruption has begun.
  • Moistens the intestinesEases a dry, hard stool during a heat illness — the same slippery action that makes it unsuitable when the stool is already loose.
  • Applied externallySteeped in sesame or another carrier oil, it is applied to burns and scalds, diaper rash, weeping eczema, and chronic ulcers; the pigment stains skin and dressings purple.

In Formulas

Formulas containing Zi Cao

Indications & Clinical Uses

  • Dusky purple macules and blood-level heat in febrile illness
    - Measles and other eruptions that fail to surface fully
    - Sore throat and toxic swellings
    - Burns, scalds, weeping eczema and slow-healing sores (external)
    - Dry stool during a heat illness

Western Medical Keywords

Searchable condition terms

BurnsEczemaMeaslesDermatitisSkin ulcer

Contraindications

Cautions

Cold and slippery, so it is wrong for a cold, weak Spleen or for anyone whose stools are already loose — it will soften them further. Stop it once a rash has fully surfaced rather than continuing out of habit. Prolonged internal use at high dose is not advised, and the purple pigment stains skin, clothing and dressings permanently.

Contraindicated in pregnancy: Use in pregnancy only under practitioner supervision — the root cools and moves the blood and loosens the stool; external application is the safer route.

For licensed practitioners’ reference only

References

  1. Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
    2. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
    3. 《中华人民共和国药典》.

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.