Franklinia alatamaha, a native plant of the Alatamaha River Valley in Georgia, USA, died out in the wild in the 1800s. But a specimen that was sent back to the Trewithen Estate, near Probus, has since been propagated and is on course to be re-introduced to the gardens.
Trewithen nursery manager Luke Hazelton has successfully encouraged the plant to flower again this year, which is unheard of in this country.
He said he hopes it survives and he is also sending them out to other gardens including Kew.
Hazelton added: "It will be really significant to plant a Franklinia alatamaha back in the garden knowing that it has come from original stock and is part of the history of the gardens."