South Indochinese BioProvince
This BioProvince (as defined by Armen Takhtajan) comprises Cambodia, the southern parts of Laos, a small part of Thailand and southern Vietnam (Cochin China). In the south, it is delimited by the lowlands of the Mekong Delta, while in the northwest it is bordered by the Chuor Phnum Dangrek Range and a limb of the Kravanh Mountains. The borders in the north and west, however, are not well defined. The geology is dominated by a crystalline basement platform of Precambrian age which gives rise to extensive plains. In central areas this platform has been uplifted to form a number of high plateaux. Prior to the erosion of an ancient mountain range in Mesozoic times the area was covered in deposits of highly metamorphosed sediments such as quartzitic sandstone and other rocks but today only scattered flat-topped sandstone hills and rounded hills of andesite and basalt remain. Many areas, such as the Rathanakiri and Chhlong plateaux were covered by basalt flows in the late Tertiary and Quaternary period and there are small, eroded volcanic cones scattered throughout the area. Much of the terrain today is covered in sands of Holocene origin. The area is largely subject to a sub-equatorial, monsoon climate with summer rain and a dry season between November and March. The rich flora includes many endemic species with about 26% of the Vietnamese endemics occurring in this area, while about 17% of the Vietnamese endemics are local endemics of this area. There are also several endemic genera including Christensonia, Eparmatostigma (Orchidaceae) and Pseudostriga (Scrophulariaceae).
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Plant Flora|