DIVERSIFIED AND VALUABLE WILD ROSES IN THE HENGDUAN MOUNTAINS, SOUTHWESTERN CHINA

China is the greatest treasure house of roses with 95 wild species and many varieties and forms of the genus Rosa. The Hengduan Mountains, located on the eastern edge of the Qinghai-Tibetan plateau in southwestern China, is a core region of the Sino-Himalayan Floristic Region and is characterized by its richness in biodiversity and endemism. Based on field expeditions undertaken since 2003, information on, e.g., the distribution and morphology of wild roses in this area has now been recorded and compiled. A summary of the results is given here: 1) There were 73 species/varieties and forms of wild roses mainly belonging to sections Rosa (formerly Cinnamomea), Synstylae, Pimpinellifoliae and Microphyllae. Among these, 43 species/varieties and forms were endemic to the Hengduan Mountains. 2) Some species were very narrowly distributed while others had a wide distribution and a large altitudinal range. Species in sections Rosa and Pimpinellifoliae occupied the higher areas from 3,000 to 4,000 m, growing scattered in forests or in alpine scrubland and meadows, while most species in Section Synstylae grew in dense stands on sunny slopes or along riversides from 2,000 to 3,000 m. 3) Many species showed morphological diversity due to natural hybridization, polyploidization and/or adaptation. 4) Wild roses embraced desirable traits such as elegant form, vivid flower color, large number of beautiful hips, pleasant scent, resistance to powdery mildew and tolerance to drought and cold weather, etc. These results suggest that wild roses in the Hengduan Mountains have great interest for research on systematics and evolution of the genus Rosa, and that they should be further investigated and preserved for direct utilization as ornamentals or as genetic resources in rose breeding.