Rhododendron wattii tree in Dzukou Valley, Nagpur that extends into the adjoining Manipur
| Photo Credit: Special Arrangement

GUWAHATI

One of the last trees of its kind standing in a popular trekking destination in Nagaland has made a silent statement — time may be running out for the Rhododendron wattii.

A study published in the Journal of Threatened Taxa focussed on the flowering phenology of a Rhododendron wattii tree in the 27 sq. km. Dzukou Valley that extends into the adjoining Manipur. Phenology is the study of how plants and animals change seasonally.

Rhododendron wattii tree in Dzukou Valley.
| Photo Credit:
Special Arrangement

The researchers noted that it was the lone tree of the species within a specified area at 2,600 metres above the mean sea level, far from the trekking route and caves that visitors frequent. The only other Rhododendron wattii reported during a field survey in 2012-13 in the Nagaland part of Dzukou Valley was felled by the locals for firewood.

Imtilila Jing and S.K. Chaturvedi of Nagaland University’s Department of Botany are the authors of the study.

Endemic to Manipur and Nagaland, the Rhododendron wattii was first collected by Sir George Watt from Nagaland’s Japfu Hill range during his 1882-85 survey. It is a small tree attaining a maximum height of 25 feet.

A view of Dzukou Valley with Rhododendron wattii.
| Photo Credit:
Special Arrangement

“Flowering occurs from the end of February to April, and fruiting is observed from April to December. The flowers present in trusses of 18-25 flowers are pink with darker flecks and purplish basal blotches,” the study said.

“No reports on this species are available from Manipur. In Nagaland, it has been reported from two areas beyond Dzukou Valley,” Ms. Jing told The Hindu.

Poor seedling survivability

There are more than 1,000 species of rhododendrons worldwide. The northeastern region has 129 of the 132 taxa recorded in India.

According to the International Union for Conservation of Nature Red List, the Rhododendron wattii is vulnerable due to population fragmentation and an area occupancy of less than 500 sq. km. However, Ashiho Asosü Mao, Director of the Botanical Survey of India, reported it to be critically endangered in its natural habitat.

The Jing-Chaturvedi study found the natural regeneration of the plant species to be very low although it produces numerous seeds after the flowers are pollinated mainly by the fire-tailed sunbird and bumble bees. Poor seedling survivability, anthropogenic activities, and wildfires — a large swathe of Dzukou Valley burnt for two weeks in 2020-21 — were among the factors responsible for the disappearance of this species.

“There is an urgent need to conserve this species by protecting its natural habitat,” Ms. Jing said.

New orchid

The rhododendron gloom in Nagaland contrasted sharply with a botanical cheer across the border in Manipur, not far from Dzukou Valley. A trio of researchers recorded Phalaenopsis wilsonii as a new member of the orchid family in the State.

A new member of the orchid family, Phalaenopsis wilsonii, in the State.
| Photo Credit:
Special Arrangement

The study by Ngasheppam Malemnganbi Chanu, Thongam Nourenpai Khanganba, and Thongam Biseshwori — all from the Institute of Bioresources and Sustainable Development in Imphal — was published in the Journal of Threatened Taxa.

The orchid was found in Chakumei, a village in Manipur’s Senapati district. It was the ninth Phalaenopsis species of the Orchidaceae family reported in the State.

The genus Phalaenopsis is represented by 80 accepted species globally, of which 18 species are known from India.