The pre-historic Wollemi pine was thought to be extinct until a specimen was found in its native Australia 12 years ago.
The pine which dates back more than 200 million years to the time of the dinosaurs, can reach a height of more than 40 metres and can live for more than 200 years.
Less than 100 of the trees - Wollemia nobilis, are known to exist in the wild at the Wollemi National Park near Sydney in Eastern Australia.
David Noble, who discovered the tree in 1994 whilst canyoning near Sydney, planted the pine at today's ceremony at Westonbirt Arboretum, near Tetbury, Gloucestershire.
Mr Noble, 41, a ranger with the New South Wales National Parks and Wildlife Service said he was honoured that the tree had been named after him.
He said: "I was out canyoning and abseiling in a gully in the Wollemi National Park when I came across the tree.
"I don't think anyone had ever stepped foot in that gully before and the tree looked very unusual so I took a sample and got it checked out."
The pine planted today will form part of an international conservation project designed to save the rare tree.
Simon Toomer, curator of Westonbirt Arboretum added: "It looks like a cross between a monkey puzzle tree and a yew tree.
"It's incredibly primitive looking and quite beautiful and with the great age the trees date from is something of a living fossil."