The Karian Shola National Park consists of areas of luxurious but stunted, mossy rainforests known as shola forests interspersed with rolling montane grassland with towering rocky cliffs, making it a biologically unique ecosystem. It is the largest such block of land in the Western Ghats and is largely undisturbed. The forest is often wreathed in mist and is important for the protection of the habitat and prevention of erosion. It contains many endangered and threatened species of plants and animals, many of which are endemic to the area. The grassland covers the greater part of the park with patches of the shola forest interspersed in the valleys and folds of the ground. The forest is affected by winds and few of the trees exceed . The trees are twisted and gnarled with contorted boughs laden with mosses, lichens, orchids and other epiphytic plants. The interior of the forest is dark and there is an understorey consisting of such shrubs as Lasianthus, Psychotria and a range of different Strobilanthes species.