Three plant species have been produced from 200-year-old seeds found in a Dutch merchant's notebook that had been sitting in The National Archives.
The Liparia villosa and Protea conocarpa seeds were carbon-dated
"Vigorous young plants" are now growing at the Millennium Seed Bank, based at Wakehurst Place in West Sussex.
The seeds were thought to have been collected during an 1803 trip to the Cape of Good Hope, on the Atlantic coast of Africa, by Jan Teerlink.
Seed ecologist Matt Daws said their germination was a "fantastic result".
"The seed was so old and had been stored in some dubious conditions [that] we really did not expect to get anything," he said.
The Royal Botanic Gardens' Millennium Seed Bank was called in when the discovery was made.
It is not known what Jan Teerlink's plans for the seeds were
Jan Teerlink's red, leather-bound notebook contained 32 different seed species in small packets.
Investigations have shown he was on board a Prussian ship when it was captured by the British navy.
All documents were passed to the High Court of Admiralty and from there, via the Tower of London, to The National Archives.
The seeds successfully germinated include 16 of the legume Liparia villosa.
One out of eight seeds of a species of Leucospermum, from the Proteaceae family, also sprouted.
The third seed germinated is believed to be from the legume Acacia.
Mr Daws said: "We'll have to wait until it flowers to find out what species it is [but] if it's a tree we may have a long wait."