Rare British daffodils may be hiding in plain sight in gardens and parks and experts want to track them down.

They have drawn up a wanted list of long-lost varieties linked to local places, such as the vibrant “bonfire yellow” daffodil associated with bonfire nights in Sussex.

Rare varieties could be lost if they’re not found and cared for, said Gwen Hines of the plant conservation charity, Plant Heritage.

“There’s the joy that they bring to all of us in the springtime … and also, in the future, they might be important for medicines for science,” she said.

Believed to have been brought to Britain by the Romans, daffodils are a source of galantamine, a treatment for Alzheimer’s disease.

The much-loved plants have been bred for centuries and now come in a dazzling array of about 30,000 different shapes, sizes and colours.

Most daffodils are yellow but some are white, orange and salmon-pink.

The gardening charity, the RHS, is asking for help in finding rare and missing daffodils that are feared lost to history and science.

The Sussex bonfire is named after the famous bonfire night in the Sussex county town of Lewes.

The daffodil is one of many bred by the local plant breeder, Noel Burr, but has not been seen for at least 20 years.

It is known for its very bright orange-yellow flower.

Sussex horticulturist Roger Parsons hopes it is still growing in a garden somewhere.

“Perhaps someone planted it in their garden and it still exists but our challenge is to find that person,” he said.

“Finding this and other daffodils thought to be lost helps maintain those genes for future plant breeding.”

This daffodil is one of many bred by the plantswoman Sarah Backhouse. It was named for her by her husband after her death in 1921.

The daffodil is unusual in being one of the first daffodils with a pinkish colour. It has a salmon-pink trumpet surrounded by ivory flowers.

The daffodil is known to exist in national collections but its actual whereabouts are unknown.

Daffodils were fashionable in late Victorian and Edwardian times, bred into different shapes and forms.

William Fowler Copeland (1872 to 1953) is a particularly well-known daffodil breeder from this time.

He named this white, double-flowered daffodil after his wife.

The RHS is also calling on the public to record where and when they see daffodils appearing this spring.

RHS scientist Dr Kálmán Könyves has spent 15 years studying “these remarkably fascinating plants”.

He said mapping which daffodils grow where will help us find out how the plants are responding to the changing climate.

“With this we can get some data on whether the flowering time changes as our climate changes,” he said.