Identification & Quality Standard
Radix et Rhizoma Rhei
Botanical Origin
The dried root and rhizome of Rheum palmatum L. or Rheum tanguticum Maxim. ex Balf, or Rheum officinale Baill. (Polygonaceae).
Production Regions
Primarily produced in the Chinese provinces of Gansu, Qinghai, Tibet, Sichuan.
Quality Requirements
Superior medicinal material is firm, with a delicate aromatic odor and a bitter and slightly astringent taste.
Macroscopic Features
Sub-cylindrical, conical, oval or irregular lumps, 3~17cm long, 3~10cm diameter. Peeled outer skin, surface is yellowish-brown to reddish-brown, some with off-white reticular striations or scattered star spots (specific vascular bundle); brown remnants of outer skin, with mostly rope-holes and rough wrinkles. Firm texture, sometimes with a slightly loose center; fractured surface is pale reddish-brown or yellowish-brown and granular. Rhizome has wide pith, with star spots arranged in whorls or scattered; xylem of root is well developed, with radial striations, cambium is obvious, without star spots. Delicately aromatic odor; bitter and slightly astringent taste, sticky and gritty when chewed.
