Indian botanists have been able to harvest two viable and healthy seeds from a 125-year-old rare double coconut tree – the only one of its kind in the country – at the Acharya Jagadish Chandra Bose Indian Botanic Garden near Kolkata.

The seeds are rare and the authorities are not taking any chances; they say they have kept the “babies” in an undisclosed location in the garden. Only three people. the director of the Botanical Survey of India, the director of the garden and a scientist (curator of the garden), are aware of the location.

“It is a major breakthrough. It was the only individual (of its kind) in India. But now we will be able to raise its second generation. This could not have happened had the tree died of any disease; the country would have lost its only double coconut tree. Both the parent plant and the seeds are now doing fine,” said Ashiho Asosii Mao, director of the Botanical Survey of India.

Efforts to raise the second generation from the lone tree, a female, started in 2006 when she was 94 years old. Pollen grains were brought from the nearest male, at the Royal Botanic Garden of Sri Lanka. The attempt failed. In 2013, pollen grains from another male were brought from Thailand. That worked, but the mother tree was attacked by a fungal infection and was virtually in a botanical intensive care unit, scientists said.

“It is a real breakthrough. More than six years of scientific efforts have yielded results. India will now have a second generation of the double coconut tree and that too ‘Made in India’. It was probably the first cross-country pollination of such a rare plant carried out with human effort,” said HS Debnath, former director of the garden, under whose tenure pollen grains were brought in from Thailand.

“While one seed, weighing around 8.5 kilograms, was harvested on February 15, another, weighing around 18 kilograms, was harvested on February 26. They have been kept in a secret chamber so that there are no chances of theft. Only three persons know the location,” said SS Hamid, curator of the garden.

The gestation period is 6.5 to 7 years — from pollination to seed maturity, says Hamid.

Double coconut trees are found only on two islands in the Seychelles. They were planted by the British in countries including India, Sri Lanka and Thailand. These palm trees can live up to 1,200 years and bear the largest fruits (weighing up to 25 kg) and leaves in the entire plant kingdom.

The garden authorities have now started preparing the nursery bed where the seeds will be planted after a few months. The authorities are also training a batch of young scientists so that they can take care of the plants when the seeds germinate.

“The seeds are now in dormant stage. It will take a few months for them to germinate. They will be planted in a guarded nursery which will have restricted access,” said Hamid.