By Subir Bhaumik
BBC News in Shillong, north-east India
The "dancing girl" - part of Mizoram culture
Botanists trying to save critically endangered plants in the eastern Himalayas for more than two decades say tissue cultures have finally brought them success in reviving some species.
The eastern Himalayas, covering India's north-eastern states and some of Burma, Bhutan and Sikkim, have been identified as one of the world's 25 bio-diversity hotspots.
India has around 49,000 plant species - around 12% of the world's known species.
Twenty percent of these are under threat of extinction. Nearly 70 of them listed as critically endangered by the Botanical Survey of India are found in the country's north-east.
"More than two decades ago, we set out to save these plant species which were on the verge of extinction. Only a few plants of these species were left," says Pramod Tandon, now vice-chancellor of the North-eastern Hill University and one of the country's leading botanists.
"We struggled to save them and then multiply them through tissue culture and now we can say we have saved many."
The Species Recovery Programme in north-east India has slowly expanded to cover most endangered plant species in the Eastern Himalayas.
Germination of the pitcher plant is very difficult
"Ours is a story of mixed success. We have successfully developed protocols for more than 20 critically endangered plants, mostly orchid varieties, and transferred them from lab to land in sufficient numbers to ensure assured multiplication," says Mr Tandon.
He is particularly pleased to have saved the "dancing girl" in the north-east state of Mizoram.
"When we started to save this one, we could locate only five to seven plants. Just one of them was in good shape," Mr Tandon told the BBC.
"Now we have developed nearly 1,000 of these orchids and successfully reintroduced them in their natural habitat in Mizoram."
"This flower is considered so important by the Mizos that I got calls from the state's governor to do something to save it from extinction. Now we can say with some certainty that there will be enough dancing girls," says Mr Tandon.
But he is quick to point out the relative lack of success in saving the Nepenthes khasiana, a pitcher plant, and Nymphaea tetragona, a lotus variety which is now almost extinct.
"This lotus variety is a hydrophyte, a water flower infested with microbes and it is so difficult to multiply them through tissue culture," says AA Mao of the Botanical Survey of India.
Germination of the pitcher plant is also very difficult.
Many of these plants have medicinal properties.
The Mantisia spathulata is used by locals for curing broken bones and dysentery. Another plant was used by the Naga separatist guerillas to treat a finger that this correspondent fractured on the way to a rebel base in 1987.
The north-east's leading cardiac surgeon, Dhaniram Baruah, says he has developed miracle compounds from two such plants he says can free arterial blockages within a few weeks and render bypass surgeries redundant.
Dr Dhaniram Baruah says he has developed miracle compounds. Photo: Subhamoy Bhattacharya
CR Deb of Nagaland University's botany department says that while researchers are increasingly using bio-technological techniques they also favour more traditional conservation methods.
The Botanical Survey's Dr Mao says: "These traditional methods involve protection of genetic resources in the natural environment through protection of the environment itself.
It is an ideal and dynamic approach that allows the plants to interact and co-evolve with other components of the ecosystem including insects, animals and microbes."
Random destruction of their natural habitats, the pressure of commercial exploitation and specific reproductive problems that some plant species suffer have been identified as the main causes for these plants being driven to the verge of extinction.
"We are doing their DNA finger-printing and molecular characterisation," says Mr Tandon.
The botanists say that some of these "saved" plants will be multiplied for commercial purposes and that could augment incomes of poor villages in remote areas of India's troubled north-east.
"But their habitats must be properly managed and random exploitation should not be allowed," says Mr Tandon.