This BioProvince (as defined by Armen Takhtajan) includes the western coastal plains (Malabar Coast) of Peninsula India from the southern vicinities of Broach to Cape Comorin, the western side of the Western Ghats (Malabar Hills) including the Anamalai, Cardamom, Nilgiri and Palni hills, and the coral Laccadive Islands. The geology is complex but includes various rock types of the Archaean group. The Varkala Tertiary formation is the most conspicuous sedimentary rock and forms cliffs fringing the west coast at several places. The area is an important part of India’s monsoonland but the boundary between this and the adjacent Deccan BioProvince to the east is not sharp and there are lots of transitional zones. Nevertheless, the level of endemism is exceptionally high with about 1272 endemic angiosperms out of a flora of about 3800 species. This constitutes about 33.5% of the Malabar flora and about 22.6% of 5725 endemics found in Indian. There are also a number of endemic genera, many of which such as Adenoon, Calacanthus, Erinocarpus, Frerea, Griffithella, Haplothismia, Jerdonia, Lamprochaenium, Nanothamnus, Polyzygus, Wagatea and Willisia are monotypic. The endemic flora is mainly palaeotropic in composition and is largely part of Indian's endemic flora of Gondwanaland origin. The characteristic endemic flora of Malabar and Sri Lanka appear to have developed from common stock but they have been largely isolated from one another due to temporal or geographic barriers for a considerable time. For example, Malabar's hill top floras of Nilgiris, Palni and Cardamom show similarities with Sri Lanka’s Adam's Peak. Three endemic 'hot spots' have been recognised - Agasthyamala, Anamalai high ranges and Silent Valley-Wayanad. There are about 189 endemic plant species reported from Agasthyamala occurring in small populations over narrow ranges. The endemic genera of Anamalai high ranges include Haplothismia, Pseudoglochidion and Utleria. However, there are a number species, such Anaphalis barnesii, Begonia aliciae, Didymocarpus macrostachya, Habenaria flabelliformis, Impatiens anaimudica, I. johnii, I. macrocarpa, I. platyadena, I. verecunda, Ophiorrhiza barnesii, O. caudata, O. munnarensis and Sonerila nemakadensis that are now critically endangered or possibly extinct. The five endemic genera occurring in the Silent Valley- Wayanad region are Baeolepis, Chandrasekharania, Kanjarum, Meteoromyrtus and Silentvalleya. The level of endemism in this BioProvince is comparable with certain oceanic islands and thought to be due to the fact that the area is isolated by the sea on its western side and by the semi-arid Deccan Plateau on its eastern side creating conditions analogous to an isolated island.
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|