Blakea attenboroughii is the official scientific name of the tree with bright-blue and white flowers, thought to exist only in Ecuador.
The tree was discovered 18 months ago by American botanist Lou Jost, who works with conservation charity World Land Trust, of which Sir David is a patron.
The trust's chief executive, John Burton, said: "Ever since scientific naming of species started it has been used to honour great contributions to biology."
The plant is compared with allied species including B. truncata, B. harlingii and B. brasiliensis.
Jost found the tree in a recently created nature reserve at Cerro Candelaria, parts of which were bought by locals with funds from the World Land Trust.
The Suffolk-based trust has helped buy and protect more than 150,000ha of biologically important and threatened lands.
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Sir David deserves everything that could be given to him. His wonderful TV series have, I'm sure, contributed enormously to the modern upsurge of interest in protecting our natural world.