This is Dryad Saddle - an edible mushroom. It gets its name from its saddle shape and the idea that tree nymphs (Dryads) used to fly about on them. You will find Dryad Saddles in woodlands from May until Autumn growing on the side of trees or dead logs. The older it is the tougher it gets so small, young mushrooms are the best to eat apparently. You fry it in butter and drain away any liquid as this can cause stomach upsets! I found this recipe on You Tube if you are interested in trying it out for yourself ... personally I think I will pass!
Deaths from mushroom poisoning in the UK are quite rare but they do occur. In 2010 a woman from the Isle of Wight died after eating Death Cap mushrooms.. She was originally from Thailand where the family were used to collecting wild mushrooms. She hadn't realised the danger as she believed that poisonous mushrooms would make boiled rice turn red.
More famously Nicholas Evans, best selling author of The Horse Whisper, almost killed himself and three close members of his family by misidentifying wild mushrooms. Again, he was used to collecting fungi so thought he knew what he was doing. Four adults (Evans, his wife, his brother in law and his wife) ate what they thought were Boletus edulis but were in fact deadly webcap. Luckily their children didn't join them for the feast - the experience would almost certainly have killed them. The mushrooms destroyed their kidneys. Three of the four adults had to have regular dialysis to stay alive. After three years Evans had a kidney transplant from his daughter because his heart began to play up.
So while I might stop to photograph the fungi on my woodland walks this Autumn, I might even enjoy their smell, I won't be touching them, or picking them or putting them anywhere near my frying pan!