Medicinals
bái wēi / 白薇 / 白薇 / black swallowwort;
Latin pharmacognostic name: Cynanchi Atrati Radix
Alternate English names: baiwei [cynanchum root]
Alternate Chinese names:
Origin: Plant
Use: medicinal
Category: Heat-clearing agents / Vacuity-heat–clearing agents
Properties: Bitter, salty; cold.
Channel entry: liver, stomach, and kidney channels.
Indications:
- Clears heat and cools the blood: Evil heat entering provisioning, yīn vacuity heat effusion, postpartum vacuity heat.
- Disinhibits urine and frees strangury (lìn): Heat strangury, blood strangury.
- Resolves toxin and treats sores: Blood heat with exuberant toxin, manifesting in toxin swelling of welling-abscesses and
sore s; venomous snake bites. - Additional actions: Bái wēi is able to clear and discharge lung heat as well as to outthrust heat from the outer body.
- It is thus used to treat patterns of lung heat with cough as well as yīn vacuity with external contraction, presenting with heat effusion and dry throat, thirst, and heart vexation.
Dosage & Method:
Oral: 3–12g in decoctions. The fresh form is preferred for the treatment of warm evil, strangury, and
Warning:
Unsuitable for spleen-stomach vacuity cold with reduced eating and sloppy stool.
Product Description:
This product takes the form of multiple roots attached to the extremity of a small rhizome. The rhizome is noded, with a rounded head bearing the scar of the removed stem. The roots are fine, cylindrical, and often contorted. They are earth brown in color, and 10–16 cm long, and roughly 1.5 mm in diameter. They break easily, revealing a whitish-yellow interior, with a darker woody core. The raw material is roughly cut into 2–3 mm lengths.
Quality:
Thick solid roots that are brown on the outside and white on the cut edge are best.
Product Area:
Liáoníng, ānhuī, Húběi.
Etymology:
The name bái wēi 白薇 is said to come from bái wēi 白微, meaning ""white fine,"" taken as description of the form and color of the root.