Rheum tanguticum, an endangered medicinal plant endemic to China

Rheum tanguticum, endemic to east part of Qinghai-Tibet Plateau in China, is one of three genuine species of rhubarb and has better medicinal quality than other two species, Rheum palmatum and Rheum officinale. The roots and rhizomes of R. tanguticum have been used for more than a thousand years in China as the well-known traditional medicines with the purgation, antibacterial, antipyretic and hemostatic effects etc. The young stems and petioles of the species are recently made as a nourishing food. However, the wild resources of R. tanguticum decrease rapid annually and the species becomes an endangered species because of the very limited distribution, poor living habitat, and over-harvest due to the increasing market request. However, since some new medicinal effects, such as antineoplastic and immune activity, were reported recently, more detailed research on the species is necessary. On the other hand, R. tanguticum is poorly known in the Western countries. The morphology, distribution, habitat, chemistry, properties, pharmacology, and planting of the species are reviewed in the present paper.