The Tanaka-Kaiyong Line-An Important Floristic Line for the Study of the Flora of East Asia

The "Tanaka-Kaiyong Line" is a line separating two floristic subkingdoms of East Asia, the Sino-Japanese to the east and the Sino-Himalayan to the west.It lies in the provinces of Sichuan and Yunnan in China.It is comprised of the "Tanaka Line of Citrus Distribution" in Yunnan province and the "Kaiyong Line of Orchid Distribution" in Sichuan province, which nearly connect at the 757 of NW Yunnan and SW Sichuan.After a survey of the distribution patterns a, we are sure that it exists.The Tanaka-Kaiyong Line is significant not only for the subdivision of the mportant floristic regions, the Hengduan Mountain region, Central China region, and Dian-Qian-Gui region, irk are noted for species abundance, endemism, and high speciation, are situated near this Line.Compared with Sino-Himalayan genera, the Sino-Japanese are more completely e by the Tanaka-Kaiyong Line, possibly due to their different florogenetic backgrounds and different times o gin.recien.it seems that the centers of biodiversity (or abundance centers) of Chinese endemic genera on seii Side of the Tan Kaiyong Line are different.The centers on the west side of the Line are m mainly paleoendemic.This difference may be caused by geological-geomorphologi climatic conditions in China.The formation of Hengduan Mountain and Yun mainly pde: but those on the east are nnan A which was induced by the uplifting of the Himalayas, greatly affected the floristic nature of western East Asia ee therefore, Uh floristic distributions that led us to define the Tanaka-Kaiyong Line have probably arisen since that t Recently in the study on the flora of East Asia it was noted that an important floristic line exists in the western part of East Asia.This line is important in the understanding of the characteristics and biodiversity of the East Asian flora.