Agastyakoodam (Agastya Malai), a towering forested peak of 1868 metres,
and adjoining forests in the tail end of Western Ghats form the most
diverse and unknown ecosystem in Peninsular India. These forests, falling
in the Kollam and Thiruvananthapuram districts of Kerala and the Tirunelveli
and Kanyakumari districts of Tamil Nadu habours many endemic species of
plants that are unique to peninsular India.
The undulating hills of these area, especially those at lower elevations, are also known for their abundance of medicinal plants. A sizable proportion of around 2000 medicinal plants used in the traditional systems of medicine are found here.
The biodiversity of the region is enhanced by the altitudinal variations. Forests occur in the altitudinal range of less than 300 metres to more than 2800 metres. In fact, the Kallar valley on the North-west of the Agasthyakoodam is one of the few remaining forested valleys below the 300 metre level in the southern tip of Indian Peninsula. The high elevation shola grasslands, on the otherhand, is unmatched in its richness of flora and fauna. They occur as an expanse around the Agasthyakoodam and also Mahendragiri and Kakkachi, two other mountains in the region. The trees here are stunted, owing to the high velocity winds lashing these mountain peaks, and often covered with lichens, mosses and ferns. These forests act as a "green house" for a wide variety of orchids, parasites and other plants.
A tribe called 'Kanis', living in these forests, are aware of generally unknown medicinal uses of some of these plants. For example, a plant known as Arogya Pacha (Tricopus zeylanicus) is used by them as a rejuvenating medicine. The wild tobacco plant (Lobelia nicotinaefolia) is used by them to heal wounds.
Of the 1300 square km of forests, more than 1000 square km are now protected
areas (wildlife sanctuaries of Neyyar, Peppara, Chenthuruny, Munduthurai and Kalakkad). However, the peak and its environs are under
constant threat of from pilgrims, tourists, trekkers, poachers, cattle grazing and illegal cutting and
collection of trees and plants. The annual pilgrimage takes place in summer.