A rare collection of poems by Sylvia Plath has been found in a box of books handed into a charity shop.

Oxfam worker Eddy Steele spotted the first-edition work, titled Ariel, as he sorted through the anonymous donation.

The hardback book was in very good condition, with its dustjacket intact and very clean.

It has been valued at £350 and is now on sale at the Oxfam Bookshop in Victoria Road, Glasgow, where it was discovered.

Mr Steele, who is manager of the store, said: "It's always exciting to find a first edition because you know you are holding something which is going to help Oxfam. In the third world £350 is a huge amount of money and can do an awful lot of good.

"The book would make an absolutely gorgeous Christmas present, and would be very unusual. Sylvia Plath books like this don't turn up that often."

As an avid fan of Sylvia Plath's work, Mr Steele recognised the valuable book straight away.

"It is the first Sylvia Plath book to come into the store since I started working here five years ago," he said.

"When I was going through the box I knew it was valuable once I saw it. I got a tingle when I picked it up."

The copy was handed in to Oxfam two months ago in a box with a mixture of general fiction and poetry.

It is thought somebody may have brought in the donation after clearing out a house.

Ariel was published posthumously following Plath's death in 1963.

This is not the first time Mr Steele has made a rare find.

"I have stumbled across a book with a difference," he said. "Last year I found a first edition of 101 Dalamations which I sold for £200. I also have a copy of King Ink, signed by Nick Cave, which I am selling for £150."

Mr Steele said other first edition versions of the book were being sold for up to £3000 on American websites.

He decided not to put the book up for auction because he felt that Oxfam customers should be given a chance to buy it.

"It's a policy I choose to run in the shop," he said. "Whenever we find a rare book I get it valued and put it on sale to give the community the opportunity to buy it first. After that it can go on ebay or be put up for auction, but I hope it sells for £350 in the shop."

Sylvia Plath was born in Boston in 1932 and published her first poem when she was eight She is often regarded by critics as the poet of death, having agonised over the death of her father, coping with depression and attempting suicide - all of which influenced her early work.

In 1956 she married the English poet Ted Hughes and gave birth to two children, but by 1963 their marriage had ended.

Later that year she killed herself with cooking gas at the age of 30 while her son and daughter where in the next room.

Two years later Ariel, a collection of some of her last poems, was published.