Some 98 per cent of our vegetable varieties have disappeared over the past century and regulations are hastening the decline, an organic charity warned today.

According to Garden Organic, 95 per cent of the vegetables we eat now come from just 20 species of plants.

Remaining traditional species from the UK and abroad are facing extinction due to EU regulations which ban the sale of seeds unless the variety is registered on a national or EU list.

Garden Organic says the loss of species threatens diversity, and consequently the security of our food.

The organic growing charity runs a Heritage Seed Library which aims to conserve and make available varieties which are disappearing, and says it has saved 800 types of vegetable from the verge of extinction.

They include oddities such as the Afghan purple carrot, Colonel Murphy beans and Ryder's Top O'The Pole, which are grown by volunteer "seed guardians" to produce the quantities of seeds needed for the library and to keep the varieties adapting to new conditions.

Colonel Murphy beans are a variety found in the colonel's garden in Porton, Wiltshire, where he grew them after obtaining them from a French girl who smuggled them out of a secret breeding station in France in her stocking during the Second World War.

Another unusual bean in the library is Ryder's Top O'The Pole, from the seed company of Samuel Ryder who donated the trophy for the Ryder Cup. It was donated by a woman who had grown the discontinued variety for more than 30 years.

The Afghan purple carrot was donated by a UN project manager in Kabul, Afghanistan. It is believed cultivated carrots originated in the country.

The pea "Carlin" has been around since Elizabethan times, and the donor's great great grandfather was given the variety as a wedding present.

It is traditionally eaten in the North of England on the Sunday before Palm Sunday - perhaps to commemorate the arrival in besieged Newcastle of a shipload of peas in 1644 saving many from starvation.

And a packet of rare Northern Queen lettuce seeds were discovered by the daughter of a market gardener amongst his "garden clutter".

Bob Sherman, director of gardens and gardening at Garden Organic, said: "The 800 endangered varieties in our living collection include all types of common vegetables such as tomatoes, carrots, beans, peas and onions - staple foods for millions of people around the world.

"And it's not just vegetable varieties we are losing but it's the local history, culture, tradition and skills that go with them.

"Once the varieties are extinct, we will never be able to get the seed or the heritage back."

He added: "Multiple varieties are imperative to protecting the food security of the nation, both now and in the future."

Members of the public can support the scheme by becoming seed guardians for the library or by "adopting" a vegetable for a year.