Darjeeling and Sikkim Himalayas are home to more than one-third of all types of rhododendrons found in India, reveals the latest publication of the Botanical Survey of India (BSI). The publication titled ‘Rhododendrons of Sikkim and Darjeeling Himalaya- An Illustrated Account’ lists 45 taxa of rhododendrons (36 species, 1 subspecies, 1 variety, and 7 natural hybrids).
There are 132 taxa (80 species, 25 subspecies and 27 varieties) of rhododendrons found in India. Of the 45 taxa recorded in the publication, 24 are found in the Darjeeling Himalayas and 44 in the Sikkim Himalayas.
The Botanical Survey of India 2017 published Rhododendron of North East India: A Pictorial Handbook, suggesting that there are 132 taxa (80 species, 25 subspecies, and 27 varieties). | Photo Credit: Photo: Special Arrangement
“Darjeeling and Sikkim Himalayas comprise only 0.3% of India’s geographical area but the region is home to one-third (34%) of all Rhododendron types. This highlights the ecological significance of the region as far as an indicator species like Rhododendron is concerned,” Rajib Gogoi, scientist and Regional Head of BSI in Sikkim and the lead author of the publication, told The Hindu.
Of the 45 taxa documented by BSI, five are facing a high threat due to anthropological pressures and climate change, according to scientists. The Rhododendron edgeworthii, with white campanulate flowers, recorded a huge habitat decline in both Darjeeling and Sikkim. Rhododendron niveum, with big purple flowers, found in the Lachung area of north Sikkim is facing threats due to rampant constructions. Rhododendron baileyi, Rhododendron lindleyi and Rhododendron maddenii are also threatened.
Rhododendron, meaning rose tree in Greek, is considered an indicator species for climate change. The BSI in 2017 published Rhododendron of North East India: A Pictorial Handbook, suggesting that there are 132 taxa (80 species, 25 subspecies, and 27 varieties). According to A. A. Mao, Director of BSI and fellow author of the publication, the flowering season for rhododendrons starts in March and continues till May. However, recently, flowering was found to begin as early as January for some species. “This is an indication that those areas are getting warmer and the phenology of rhododendrons can be an important indicator of climate change,” he added.
The first Rhododendron species from northeast India — Rhododendron dalhousiae — was reported from Sikkim by Joseph D. Hooker in 1848 in his book The Rhododendrons of Sikkim Himalaya. | Photo Credit: Photo: Special Arrangement
It also has a prominent place in the country’s botanical history. Rhododendrons were first recorded by Captain Hardwick in Jammu and Kashmir in 1776 where he spotted the Rhododendron arboreum. However, it was a visit by the British botanist Joseph D. Hooker to Sikkim between 1848 and 1850 that revealed the rhododendron wealth of the Sikkim and Darjeeling Himalayas.
“Joseph D. Hooker during his expedition to Darjeeling and Sikkim discovered 22 species of Rhododendrons. During that period paintings of Rhododendrons were commissioned to identify these species. Where these publications came before the western world, not only were botanists amazed by the beauty and variety of these flowering plants but the phenomenon led to a boost in botanical exploration in the country,” Mr. Gogoi said.
Mr. Mao added that the first species of Rhododendron from northeast India — Rhododendron dalhousiae — was reported from Sikkim by Hooker in 1848 in his book The Rhododendrons of Sikkim Himalaya. This publication almost 160 years ago made these flowers very popular in the western world and resulted in horticulture boom in Europe.
Of the 45 taxa of Rhododendrons documented by the Botanical Survey of India, five are facing a high threat due to anthropological pressures and climate change, according to scientists. | Photo Credit: Photo: Special Arrangement
“The publication has a number of historical references to the contribution of British botanists Joseph D. Hooker and David G. Long as well Indian botanists and researchers S.T. Lachungpa, U.C. Pradhan and K.C. Pradhan among others. These people played a crucial role in discovery and identification of Rhododendrons in Sikkim and Darjeeling Himalayas,” he said.
Mr. Mao pointed out that the publication has a number of pictorial references of rhododendron habitats through the years. The other authors of the publication include scientists and researchers Norbu Sherpa, Samuel Rai and Subrata Gupta.
British botanists Joseph D. Hooker and David G. Long as well as Indian botanists and researchers S.T. Lachungpa, U.C. Pradhan, and K.C. Pradhan played a crucial role in the discovery and identification of Rhododendrons in Sikkim and Darjeeling Himalayas. | Photo Credit: Photo: Special Arrangement
The authors are working on a book on rhododendron, with which they hope to reach not just researchers but the common man too, in an attempt to promote eco-tourism from a conservative perspective.
The publication lists seven natural hybrids in the region and the authors said their presence is a reminder that the Sikkim Himalayan region is a living laboratory of evolution and speciation as far as rhododendrons are concerned.
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