Floristic Notes and Chromosome Numbers of Some Chinese Roscoea (Zingiberaceae)

Abstract

Roscoea J. E. Smith (Zingiberaceae) is a genus of 17 species of tuberous-rooted rhizomatous herbs, distributed across and beyond the Himalayas, the eastern limits being in southwest China in Sichuan and Yunnan provinces. The altitudinal range is 1200-4880 m. The genus has been revised by Cowley (1982), but there is a need for a cytological investigation. There are already some published counts (Bhattacharyya, 1968, Bisson et al., 1968, Mahanty, 1970, Mehra, 1971, Chen et al., 1986, 1987). These appear to be uniform at 2n = 24, with one instance of polyploidy, and one of 2n = 26 by Mahanty (1970) in R. purpurea Sm. (syn. R. procera Wall.). Roscoea is unique in the Zingiberaceae in being the only genus that is truly hardy in Europe, occurring as it does at high altitudes in subtropical and warmtemperate zones. Plants which were collected on the CLD (Chungtien, Lijiang, Dali) expedition flowered the following year, and their identity was confirmed.