According to a recent research review
published in the Journal of Threatened Taxa, Western Ghats, one of the eight
hottest biodiversity hotspots in the world, harbours highest number of endemic
orchid species found in Peninsular India. 123 species among the 130 endemic
orchid species of peninsular India are found in different parts of Western
Ghats, says the study. Among them, 95 species are strictly restricted to Western Ghats.
 |
| A terrestrial orchid species found in Western Ghats |
|  |
| Flowers of a terrestrial orchid in Western Ghats |
Peninsular India is the region is bordered
by Vindhyan mountain range in the north, Arabian Sea in the west, Indian Ocean
in the south and Bay of Bengal in the east and comprises of seven Indian states
– Andhra Pradesh, Goa, Karnataka, Kerala, Maharashtra, Odisha and Tamil Nadu
and union territory - Pondicherry. Geographically, peninsular India is divided
into Western Ghats, Eastern Ghats and Deccan Plateau.
Kerala
shelters maximum number of endemic orchids in Western Ghats
According to the study, Kerala part of
Western Ghats has maximum number of endemic orchid species. Agasthyamalai-hills,
Anamalai-High Ranges, Nilgiri-Silent Valley-Kodagu region are some of the
important regions here which support high endemism, says the paper.
 |
| State-wise distribution of endemic orchids in Western Ghats |
The present study also points out the high
endemism among orchids found in Western Ghats. Of the 123 endemic orchids found
in Western Ghats, 95 are strictly restricted to these mountain ranges. At the
same time, among the 22 species of endemic orchids found in Eastern Ghats, only
5 species are strictly endemic. None among the 29 endemic orchids reported from
Deccan Plateau are restricted to the plateau.
Endemic
orchid fauna of Peninsular India
According to a study, the family of orchid
like plants have 22500 different species across the world. Among them, 1331
species are reported from India. 404 species among them are endemic to
India.
The present study claims that the actual
number of endemic orchid species at peninsular region is 130 which are
distributed into 38 genera. Among them, 43 are ground orchids, 85 are epiphytic
or grow on trees and two are holomycotrophic (grows on dead or decaying
matter).
In the past, different studies have come
out with different figures about the endemism among orchids in the region.
However, the authors of the present study claims that they have updated the
list by including latest changes in the taxonomy and updated distribution data
for many orchid species.
According to the paper, many species which
were earlier considered as endemic were later reported from other regions also.
“A total of 27 orchid species
earlier considered as endemic to the peninsular region are excluded from the
list owing to their extended distribution in the neighbouring countries”, says
the paper.
Threats
to endemic orchid fauna in peninsular India
According to the study, different forms of
human intervention like cattle grazing, mining, construction activities and
forest fires are the major threats to these endemic orchids in the peninsular
region.
