These rich forests of the Andaman and Nicobar islands situated in the Bay of Bengal typically show three stories. The upper story or canopy is formed by gigantic trees reaching heights of up to 60 m, and includes endemic species such as Canarium mani (Burseraceae), Dipterocarpus kerrii (Dipterocarpaceae), Hopea andamanica (Dipterocarpaceae), Myristica andamanica (Myristicaceae), Planchonia andamanica (Lecythidaceae), Xanthophyllum andamanicum (Polygalaceae) as well as Dipterocarpus incanus, Hopea odorata, Sideroxylon longipetiolatum, while on the Nicobars these would include the endemic Bentinckia nicobarica (Arecaceae). Below the canopy is a tier of trees whose heights vary between 20-30 m. Prominent among these are Dillenia pentagyna, Duabanga sonneratioides, Litsaea panamonja, Myristica irya, Pisonia excelsa, Powetia pinnata, and the endemic Ailanthus kurzii (Simaroubaceae) and Lagerstroemia hypoleuca (Lythraceae). The lower most tree layer includes various shade tolerant species such as Fragraea morindaefolia, Macaranga tanarius, Mitrephora prainii, the endemic Drypetes andamanica (Putranjivaceae) and Orophea hexandra (Annonaceae), and the near endemic Garcinia andamanica (Clusiaceae), Pandanus andamanensium (Pandanaceae) and Talauma andamanica (Magnoliaceae). On the Nicobars these smaller trees typically include the endemic or near endemic Apodytes andamanica (Icacinaceae) and Ochna andamanica (Ochnaceae). Important species in the shrub layer are Areca triandra, Clerodendrum viscosum, Clinogyne grandis, Leea indica, the endemic taxa Glycosmis pentaphylla var. andamanensis (Rutaceae), Maesa andamanica (Myrsinaceae) and Peristrophe andamanica (Acanthaceae), and the near endemic Polyalthia andamanica (Annonaceae).  Most of the arborescent species throughout these forests are heavily laden with woody climbers including the ancient Gnetum scandens, the endemic Mezoneuron andamanicum (Fabaceae) and the endemic climbing bamboo Dinochloa andamanica (Poaceae). There are also many epiphytic species especially ferns and orchids. On the Nicobars these include the endemic orchid Trichoglottis quadricornuta (Orchidaceae). Also endemic to these forests is the magnificent ground orchid Phalaenopsis speciosa (Orchidaceae). Finally, an unusual feature of these tropical, evergreen forests is the lack of tree ferns.

The Nicobars have a type of evergreen forest occurring on raised coral reefs. These differ in character from the more inland forests. The tree species typically include the endemic Orophaea katschallica (Annonaceae) and the near endemic Aglaia andamanica (Meliaceae) and Apodytes andamanica (Icacinaceae), while the shrubby growth includes the near endemic Psychotria andamanica and P. nicobarica (Rubiaceae).

 

References

Dagar, J. C. & Singh, N. T. 1999. Plant resources of the Andaman and Nicobar islands. Bishen Singh Mahendra Pal Singh.

Kurz, S. 1876. A sketch of the vegetation of the Nicobar Islands. Journal of the Asiatic Society of Bengal, 45: 105-164.

Nayar, M. P. 1996. “Hot Spots” of endemic plants of India, Nepal and Bhutan. Tropical Botanic Garden and Research Institute. Palode, Thiruvananthapuram.

Renvoize, S. A. 1979. The origins of Indian Ocean Island floras. In: Plants and Islands. Ed. D. Bramwell. Academic Press.

Thothathri, K. 1960. Studies on the flora of the Andaman Islands. Bulletin of the Botanical Survey of India, 2: 375-373.

Thothathri, K. 1962. Contribution to the flora of the Andaman and Nicobar islands. Bulletin of the Botanical Survey of India, 4: 281-296.