Wiseman’s Chinese Medical Database

zǐ cǎo / 紫草 / 紫草 / arnebia/lithospermum;

Latin pharmacognostic name: Arnebiae/Lithospermi Radix

Alternate English names: puccoon

Alternate Chinese names: 紫草根 zǐ cǎo gēn

Origin: Plant

Use: medicinal and alimentary

Category: Heat-clearing agents / Heat-clearing blood-cooling agents

Properties: Sweet, salty; cold.

Channel entry: liver and heart channels.

Indications:

Cools the blood and quickens the blood, resolves toxin and outthrusts papules: Purple-black maculopapular eruption, measles failing to erupt; also used for welling- and flat-abscesses (yōng jū) and sores, eczema, pudendal itch, burns and scalds.

Dosage & Method:

Oral: 3–10g in decoctions. For external use, it is either steeped in oil or boiled down to make a paste.

Warning:

Zǐ cǎo is cold and lubricating in nature and has a mild draining effect. Thus, it is contraindicated in spleen vacuity with sloppy stool. A contraceptive effect is sometimes mentioned in the literature; this appears to be based upon a study conducted in 1964 that reported 82.4% efficacy when using zǐ cǎo orally as a female contraceptive.

Notes:

软紫草, from Arnebia euchroma (Royle) Johnst., is considered slightly better than yìng zǐ cǎo, and it is more commonly sold on the market. 硬紫草, from Lithospermum erythrorhizon Sieb. et Zucc., is considered acceptable but slightly inferior to arnebia. A great deal of the product sold on the Western market as zǐ cǎo is not from either of the official plants listed in the Chinese pharmacopoeia, but rather is a plant known as běi zǐ cǎo 北紫草, also called 委陵菜. This is readily distinguished from standard 紫草 by being a mixture of herb and root material and by having a less pronounced purple color.

Product Description:

Arnebia euchroma (soft puccoon): This root is contorted, spindle-shaped, 8–15 cm long and 1.5–2 cm in diameter. It has a blackish maroon or purple coloring, a loose skin, and an interior is composed of 10 or more flaky layers. It is light, and easily breaks and has a slightly sour smell. The decocting pieces are 1.5 cm sections. Lithospermum erythrorhizon (hard puccoon): This is a contorted cylindrical or spindle-shaped root, 7–15 cm long and 0.7 cm thick, with remains of the stem at the base, often bearing side roots. The exterior surface is dark purple, rough, with longitudinal furrows. The skin is thin and slightly scaly. This root is relative hard but light and brittle. The cross section reveals the purple skin contrasting and partially separated from the pale brown woody core.

Quality:

Clean, large, fat roots that are deep purple in color, and have no remains of the stem attached are the best.

Product Area:

Xīnjiāng, Tibet, Gānsū, and Japan.

Etymology:

The name zǐ cǎo 紫草, literally ""purple herb,"" reflects the color of this item.