“We expected a good response, because I think the book is a good book, but I don’t think we expected him to be as popular as he was,” said Joanne Potter, marketing manager of Merlin Unwin Books, which is based in the town’s Corve Street.

“We are incredibly pleased. There are some beautifully produced books including about 1,000 mushrooms and fungi which are not edible or are not good to eat and are poisonous. But in his book Alex comes at it from the other direction and concentrates on positive identification and how to pick 12 safe ones. It’s quality, not quantity.

“We got to know Alex because he submitted a manuscript to us for a book called Hook, Line and Sinker about fishing and philosophy, and whether or not fish feel pain. Alex is a philosopher with a philosophy degree. So we did this book.

“One of his hobbies is mushrooming, and he came up with this concept of mushrooming without fear.

“Mushrooming is taken very seriously in Eastern European countries and places like Switzerland and, from talking to people he has met in the UK, he realised people have such fear about it and he came up with this idea of giving people almost a foolproof way of picking mushrooms. That is why there are only 12 mushrooms in the book.

“His rule number one is never to pick a mushroom with gills.”

Apart from identifying safe mushrooms, the book includes sections on how to handle, store, and cook them.

Alex, who is 53 and a professional writer, explained that the book arose from walks with the publishers in the Mortimer Forest, near Ludlow, in which he pointed out the various mushrooms as he went along.

“They said: ‘Couldn’t you write a book and explain it in the way you explain it to us?’ I love collecting them, picking them, and cooking them.

“You can make a meal with mushrooms alone, if you mix them with pasta for example. It’s quite delicious.”

His talks at the Ludlow festival had been met by full houses, he added. He returns to Switzerland tomorrow.

But what was the Mortimer Forest like for mushrooms?

“I shouldn’t tell you this, but it’s great. There are some excellent areas.”

Among Alex’s tips for safe mushrooming are:

lNever, never take a mushroom with gills. “This is our life insurance.”

lOnly take mushrooms with tubes, spines and ridges.

lOnly eat mushrooms which you have clearly identified.

lIf a mushroom smells rotten, it is rotten, and if it feels soggy, it is soggy.

lNever, never eat wild mushrooms raw.

lIf in doubt, leave it.

Mushrooming Without Fear is hardback, with 128 full colour pages, and costs £14.99. The ISBN is 1 873674 88 0.