North Indochinese BioProvince
This BioProvince (as defined by Armen Takhtajan) comprises the tropical parts of Laos and northern Vietnam (including northern Annam). Mountains cover much of the area with the highest formations along the Laos-Vietnam border. The peaks including Xai Lai Leng (2711 m), Phu Hoat (2452 m) and Rao Co (2235 m) are largely composed of Triassic granite. There is also a chain of ancient (Palaeozoic and Mesozoic) limestone plateaux along the Song Da (Black) River including Sin Ho, Son La and Moc Chau with elevations ranging from 1500-1700 m. The climate is classed as tropical monsoon with cold winters and much of the rain falls in summer and autumn. The flora includes several endemic genera such as Diphyllarium and Petelotiella, and a multitude of endemic species including the unusual Plantanus kerrii, which differs from other species of the genus in having pinnately veined, toothed leaves. The orchid flora is particularly rich with over 200 species from 77 genera and including the monotypic, endemic genus Vietorchis and 12 locally endemic species. Another interesting feature of the flora is the large number of relict Tertiary species particularly in the mountain forests. These are remnants of a flora that occupied wide tropical and subtropical areas of Europe, Asia and North America some 40-70 million years ago.
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|