The BRT Tiger Reserve is on the easternmost edge of the Western Ghats. The reserve gets its name from the white hill on which the popular Biligiri Ranganathaswamy temple is located, and serves as a link between the Eastern and the Western Ghats. The southern range of the tiger reserve has high altitude grasslands called Sholas at its very top, that run into evergreen patches of forest. This mosaic of Sholas and thick evergreen patches houses a rich diversity of wildlife.
The grasslands are so large that herds of giant elephants can hide easily within them.
The forests patches that the grasslands run into are so thick, that their canopies make large eagle nests a small speck in their midst.
All of the wild flora and fauna apart, the altitude and climate of the landscape are also ideal for coffee cultivation.
A number of people work in the coffee plantations through the day. However, the plantations don’t contain just coffee; they have their share of native forest vegetation as well, ensuring that animals still have some of their natural habitat.
For a few weeks every year, this mosaic of forests, coffee plantations and Shola grasslands witnesses a fascinating natural phenomenon. When the monsoons are at their peak, the lush green forests are contrasted with thick carpets of yellow and white, because of the mass flowering of an orchid.
A number of trees in the forests and coffee plantations alike can be seen adorned with natural bouquets of these white orchids. On some trees, the orchids grow all along the bark, extending to the very top of the tree trunk, as far as the eyes can see.
Scientifically classified under the family Orchidaceae, orchids are one of the largest families of flowering plants. There are over 28,000 species of orchids in the world, distributed across over 750 genera. In India, there are over a 1000 species of orchids belonging to over 180 genera. While the Western Ghats are home over 300 species of these species, it has as much as 46% of India’s endemic orchids.
Source: http://www.kiran.nic.in/pdf/IJHF/Vol27_1/16-Diversityconservationrare_endemic.pdf, Conservation of Wild Orchids of Kodagu in the Western Ghats by Dr. T. Ananda Rao
The species of orchid that blooms in these large numbers is called the Coelogyne nervosa, or the Veined Coelogyne. It is a small to medium sized epiphyte (an organism that grows on the surface of a plant and derives its nutrients and moisture from the atmosphere, using the host only for support, without necessarily affecting the host negatively) with five white petals, about 3 cm long. It has a column about 2.5 cm long, which is bright yellow in the centre. This species of orchid is an endemic species found in the Western Ghats that run through the states of Karnataka, Tamil Nadu and Kerala. It is known to flower from May through September.
The Veined Coelogyne is characterised by a pseudobulb, which is yellowish and conical. The pseudobulbs first start appearing on the host trees in large numbers. While the commonly known host trees are Careya arborea Roxb. and Ligustrum sp., during the mass flowering, they are found on a number of trees including the Silver Oaks (Grevillea robusta) that are common in coffee estates.
At times, a tree trunk accommodates so many of these yellow psuedobulbs on it, that one can barely see any part of the trunk.
The leaves then make way from a psedobulb. Each psuedobulb accommodates exactly two leaves, which are about 2-4 cm in length.
Once both the leaves make their way out, the flower comes into bloom.
Then, when the flower blooms, the pseudobulbs become more green and corrugated than the rich yellow that they first appeared as. Eventually, entire trunks are covered in blooming orchids, or orchids in various stages of growth, such as on this tree, with the bottom part of the trunk with pseudobulbs, and the top part with flowers that have bloomed.
While not much is known about the reasons for this mass-flowering, even less is known about its significance. It makes me wonder what a two-week window in which so many orchids of one species bloom possibly implies. It takes me back to what we’ve been told about the Western Ghats – it isn’t a single homogenous habitat, as much as it is a collection of niches, each niche being an ecosystem in itself. Probably, when an endemic species blooms the way this orchid does, every year, it is a sign of that little ecosystem still holding its own against everything that we’ve thrown at it, be it climate change or coffee estates.
And in the times that we live in, any signs of an ecosystem doing well are welcome.