Qumazi is a commonly used Tibetan medicine. With a long history, it can be found in the Four Medical Tantras written by gYu-thog rNying-ma Yon-tan mGon-po since the 8th century AD. Qumazi grows in mudflats and fields, including species growing in highlands, lowlands, mountains and farmlands. According to records in Crystal Beads Materia Medica, it features green sword-shaped leaves, thin stems with red veins, inserted panicles, white chicken-like flowers and copper needle row-like roots. However, there are many inconsistent morphological descriptions for Qumazi plants in many Chinese versions of Tibetan medicine books. In this article, after studying ancient and modern Tibetan medicine books, consulting experts and conducting surveys, the authors confirmed that Qumazi belongs to Rheum of Polygonaceae, including Rheum nobile Hook. f. et. Thoms, R. globulosum Gage, R. alexandrae Hook. f. et. Thoms, R. pumilum Maxim and R. delavayi Franch. In some regions, Qumazi is substituted by R. spiciforme Royle and R. przewalskyi Losinsk. After the Chinese version of Qinghai-Tibet Plateau Drug Illustrations was published in 1972, Qumazi has been miswritten as P. sibiricum Laxm in many Chinese versions of Tibetan medicine books, perhaps because P. sibiricum Laxm has many similar features with Qumazi as described in Crystal Beads Materia Medica and then is mistranslated from Tibetan to Chinese versions. According to records, Qumazi can reduce edema and is mainly applied to treat the minamata disease in clinic.
China ; History, Ancient ; Medicine, Tibetan Traditional ; history ; Plants, Medicinal ; chemistry ; growth & development ; Polygonaceae ; anatomy & histology ; chemistry ; growth & development ; Reference Books, Medical

Objective To explore the method to control the quality of Rheum nobile. , a widely used Tibet-an herbal medicine. Methods The herb powder of ten batches of Rheum nobile was identified by thin layer chromatography ( TLC) with piceatannol-4′-O-β-D-glucopyranoside as the reference substance, and the moisture content, total ash and acid-insoluble ash were detected in accordance with Appendix IX of Chinese Pharmacopoeia 2010 Edition. The contents of piceatannol-4′-O-β-D-glucopyranoside and res-veratrol-4′-O-β-D-glucopyranoside were determined by using HPLC. Results The spots of piceatannol-4′-O-β-D-glucopyranoside of ten batches of Rheum nobile were clear and well separated. The range of moisture content was from 7 . 46% to 9 . 14%, and that of total ash was 2 . 72% to 8 . 75%, and that of acid-insoluble ash 0 . 50% to 2 . 51%. The content of piceatannol-4′-O-β-D-glucopyranoside was showed a good linear relationship at the range of 1 . 768 to 70 . 720 mg/L ( r=0 . 999 8 ) and the recovery rate was 101. 11% ( RSD =0. 89%), by parallel, that of resveratrol-4′-O-β-D-glucopyranoside was showed a good linear relationship at the range from 0 . 416 to 16 . 640 mg/L ( r=0 . 999 6 ) and the recovery rate was 99. 68% (RSD=2. 54%). Conclusion The methods of TLC and HPLC are simple, accurate and re-peatable, which could be the option of the quality control of Rheum nobile.