What it is:
This herb is the smoked unripe fruit (green plum) of Prunus mume (Sieb.) Sieb. et Zucc. (family Rosaceae) which is produced mainly in Zhejiang, Fujian andYunnan provinces. It is collected in summer and baked with mild heat till the pulp looks yellowish brown, and then covered tightly while hot till the pulp looks black. The black plum is dried in the sun after removal of the nucleus and used without further preparation or stir-baked to charcoal.

Property
Flavour and channel tropism: sour in flavour, neutral in property, acting on the liver, spleen, lung and large intestine channels.

Effects:

Astringing the lung to relieve cough, astringing the bowels to stop bowels to stop diarrhea, promoting the production of body fluid to quench thirst, and regulating the stomach to alleviate colic caused by ascariasis.

Used For:
1. To relieve protracted cough due to deficiency of the lung, it is often used with poppy capsule, pinellia tuber, bitter apricot kernel and donkey-hide gelatin, as in Only One Dose Powder (Yifu San).

2. To arrest chronic diarrhea and dysentery, it is often used with nutmeg, dangshen and chebula fruit, as in Pill for Reinforcing the Intestines (Gchang Wan).

3. For the treatment of diabetes due to heat of deficiency type, it is often used with trichosanthes root, ophiopogonroot and gin seng , as in Jade Spring Pill (Yuquan Wan).

4. To relieve abdominal colic and vomiting caused by ascariasis, it is often used with asarum, prickly-ash peel, dried ginger and coptis root, as in Black Plum Bolus (Wumei Wan). This herb also has hemostatic function and can be used in treating hemafecia, hematuria, metrorrhagia and metrostaxis; used externally, it can subdue swellings and cure ophthalmic pterygium.

Precautions:
Blackplum has a strong astringent action, so it should not be prescribed to patients with residual pathogenic factors in the exterior and heat of excessive type and stagnancy in the interior.