Cylindrophyllum hallii in all its glory

Dr Smith said: "Owing to its unusual appearance this attractive plant has been over-collected.

"It is now threatened in the wild and has not been seen in the region since 1954. Many people thought it lost for ever.

"We spent a whole day searching for it, with no success.

"Finally, on the point of giving up, we asked a local shepherd, who immediately recognised the plant we were looking for and directed us to a very healthy population."

He and his colleagues found about a thousand plants, concentrated on a steep mountainside. There were no seeds for them to collect, but they documented the discovery thoroughly so that the plants can now be closely monitored.

The other plant they found is a member of the Mesembryanthemaceae, Cylindrophyllum hallii L. Bolus. It belongs to the family of Namaqua daisies, and is described as of great botanical interest: its sister species all come from the Little Karoo desert.

Ravaged

Dr Smith said: "This population has not been documented or collected since 1960, and we were very excited to find it.

"Only about 219 living plants were left, with clear signs of having been ravaged. We saw many dead plants though, possibly victims of drought or destruction by animals feeding."

But there were plenty of seeds, and the team took less than 5% of what was available.

Safe haven in the seed bank

"This is exactly the kind of species that needs conservation off-site in the millennium seed bank", Dr Smith said. "The seeds will be safely stored in our vaults."

The seed bank will work out its germination method so that, if the wild plants do vanish, the seeds can be successfully reintroduced.

Dr Smith told BBC News Online: "There is certainly a good chance of finding other similar plants.

"There's an element of luck about it, obviously. And it is the more obscure plants that are likely to go under.

"We have a programme continuing over the next five years, and we shall certainly be looking for other plants which at the moment we believe to be extinct."

South African photos courtesy of Dr Paul Smith, Royal Botanic Gardens, Kew