A Scottish plant collector George Sherriff first sighted Rhododendron pogonophyllum at Tangchhu in 1937. Since then, despite several attempts, except for existing as ‘data deficient’ in the botany books, finding it was an arduous task. Until recently.
In the first week of this month, a team consisting of six people from the National Biodiversity Centre (NBC) made another attempt to look for the species.
The records about the places of species sighting left by the Scots were vague and no longer exist, said a curator with NBC Phuentsho. Before venturing out, with the help of David Long from the Royal Botanic Garden Edinburgh and Pam Eveleigh from the Primula World, the locality was traced to Kyitsugang, Dangchu in Wangdue.
Sheriff, in his records, noted Kyitsugang as Chizukang. The species he collected as Rhododendron pogonophyllum was mistaken for Rhododendron hypenanthum which is now considered as a subspecies of Rhododendron anthopogon (balu sulu). Later in July the same year, Sheriff also collected the same rhododendron species from Rinchen Chu noted as Chore in central Bhutan.
Rhododendron pogonophyllum is a creeping subshrub which has similar flowers to that of Rhododendron anthopogon with small obovate leaves with rounded or retuse apex, rounded at base and scaly leaf underside.
“But it is smaller in size,” said Phuentsho.
Currently, Chore is known as Khero to the locals and the present day Nikachhu was known as Rinchenchhu. Such mistakes in the history of the places and its vernacular had impeded the earlier expeditions in finding the species, Phuentsho said. “In earlier attempts, surveys were carried out in Bumthang mistaking Tangchu as being located in Bumthang Tang.”
He said that climbing alpine scree with narrow gorges above 4,000 metres above sea level in the peak of the monsoon was not an easy task. “Footpaths are barely visible since people no longer use the area as a grazing land throughout the year. The team took shelter in the wooden huts of the cow herders from Dangchu and ascended through steep cliffs towards Kyitsugang.”
However, the struggle was not in vain. Rinchen Dorji from the team approached a high area to connect his phone to the network when he spotted the species flowering precariously on the rocks and rocky soils on open hillsides at Kyitsugang at an altitude of 4,452 masl. Rhododendron pogonophyllum was rediscovered after 84 years in Bhutan.
Dangchup’s consider Kyitsugang as the abode of their deity Kyitsub.
Rinchen Dorji said that the team was focused on finding the species that physical challenges no longer bothered them. “I was elated upon seeing it. It was small and almost invisible.”
Except for one reported sighting in China, Rhododendron pogonophyllum is listed as a rare endemic plant to Bhutan. “Plants Endemic to Bhutan Himalaya’’ by the NBC published in 2015 listed it as one of the endemic plant species found in the country. The Flora of Bhutan describes a total of 46 species out of which 45 are known to be occurring in Bhutan.
Although there are chances that it could exist in other parts of the country, it is a restrictive plant, confined to one area, said Phuentsho.
However, he said that due to the plant’s occurrence on cliffs and precipice, there was less disturbance from livestock and wild animals. “The main risk is climate change. With rapid warming, the plant cannot thrive.”
The specimens collected is deposited in the National Herbarium, the official botanical repository and reference centre of the country. The repository currently has about 16,000 specimens.
Phuentsho said that there were possibilities to make the species information available to the International Union for Conservation of Nature which lists it as ‘data deficient’.
Edited by Jigme Wangchuk