A lantern is shining in Assam after 145 years.

Researchers from the botany department of Gauhati University have spotted Ceropegia lucida wall, commonly known as the luminous lantern flower, in Golaghat district of Upper Assam.

It was first found by R.L. Keenan, an employee of the Royal Botanic Garden, in June 1874, in Cachar after which it was neither collected nor reported from anywhere within the state. It was categorised as “regionally extinct” as it was not located in its site of occurrence.

Debolina Dey, a researcher in the department of botany, Gauhati University, said the luminous lantern flower appears to be a bright and illuminated lantern in the dark. The other researchers are Manash Baruah (research scholar), Nilakshee Devi (head of the department, department of botany) and Jitendra Nath Borah, the executive president of the All Sanchi Growers Association of Assam.

The team has reported the sighting in the current issue of Journal of Threatened Taxa. The flower was found during a recent survey in Golaghat district from August to October 2018, when the researchers came across many interesting plant specimens. On consultation with the existing literature and herbarium specimens, it was found to be the Ceropegia lucida wall.

The plant was twining around an abandoned streamside land mass in the district. The twiner grew in close association with bamboo, ferns and other climbers. Only five to six flowers were observed growing in a single population.

“Of 61 taxa reported from India, only a handful, nine taxa to be precise, are found in the Northeast. This can be considered a celebrity plant genus among taxonomists throughout the globe because of its beautiful flowers, rarity in occurrence and mysterious fly-induced pollination systems,” she said.

“Literature says that the flask-shaped flowers belonging to the genus Ceropegia evolve in such a way that small Diptera flies (mainly females) gets lured by the critical structure of the flower. They therefore get trapped inside and cause pollination. Such biological interaction between plants and insects can be a great scope of research for the upcoming ecology and environmental research workers,” she said.

The leaves are bright green and the flowers are 1.2cm to 3.2cm long, greenish or yellowish-white with purple spots. It flowers from September to November and is found in Namdapha National Park in Arunachal Pradesh, Cachar and Golaghat in Assam, Khasi Hills in Meghalaya, Sikkim, Bangladesh, Myanmar, Thailand, Malaysia, and China.

“The flower is mostly found in the Western Ghats where extensive work has been done. In the Northeast’s hotspots, I believe more taxa should be present in the wild that calls for thorough research work by young workers/taxonomists of the state,” she added.