A rare species of tree dating back millions of years has been planted at Kew's Royal Botanical Gardens by wildlife expert Sir David Attenborough.
Sir David Attenborough planted a Wollemi pine at Kew Gardens
The Wollemi pine, once thought to have been extinct for 200 million years, was recently discovered in Australia, sparking a major conservation project.
It is thought the pines populated the ancient supercontinent Gondwana when dinosaurs walked the Earth.
The tree will also be displayed at the RHS Chelsea Flower Show in London.
Planting the rare tree Sir David said: "How marvellous and exciting that we should have discovered this rare survivor from such an ancient past.
"It is romantic, I think, that something has survived 200 million years unchanged.
"There are other plants that come from that period; but to suddenly find not just a new species but a new genus, too, is really quite exciting."
On the same day Actor Kenneth Branagh was to plant a Wollemi pine (Wollemia nobilis) at Wakehurst Place, Kew's country garden in Sussex, where seeds are already preserved in the Millennium Seed Bank.
A tall conifer, it is closely related to the monkey puzzle tree, and has an unusual pattern of branching, with the mature foliage having two ranks of leaves along the branches.
Fewer than 100 adult trees are known to exist in the wild and the exact location of Wollemi groves remain a secret.
Tony Kirkham, head of the arboretum at Kew, is one of the few people who have been allowed to see the tree in their natural habitat.
"It's important to show this tree to people outside of Australia - to highlight its importance," he told BBC News. "We are doing a hardiness trial for the Australians.
Saplings will go on sale to the public next year
"We've got 30 trees planted out here at Kew and at Wakehurst Place, and we'll run them for 18 months to see how they adapt to our climate.
"They've experienced minus 12 Celsius in North America this winter and, certainly, minus five in Sydney. So, they should be OK here."
From next year Wollemi pine saplings will go on sale to the public, and some of the revenue will be sent to Australia to help fund future conservation efforts.