Identification of Rhodiolas used in Tibetan Medicine

I am currently helping Dr Tsering Norbu, Director, Materia Medica (Medicinal Plants) Department of The Dalai Lama's Tibetan Medical & Astrological Institute in Dharamsala, N.India with providing Scientific Identifications for hundreds of Himalayan species utilised in Tibetan Medicine. I would welcome any suggestions for the Rhodiolas which he provided images off from Spiti, borderlands of W.Tibet and Nepal.

The late Dr Ralph Stewart (who lived to be 102) got his doctorate from Columbia University in 1916-17 on the 'Flora of Ladakh' (known as Little Tibet, which I am visiting this fall). He worked as a Presbyterian Missionary, then Principal of Gordon College, Rawalpindi, Pakistan - in his spare time he explored for plants. Upon retirement he was Research Associate at Ann Arbor, MICH. Within his life's botanical work: AN ANNOTATATED CATALOGUE OF THE VASCULAR PLANTS OF W.PAKISTAN AND KASHMIR (running to 1028 pages). He presented me with his final, personally annotated copy when I visited him a his retirement home in CA in 1983; this has been invaluable to me but Crassulaceae are a challenging family identification-wise........