When you think of fungi, it is hard not to think of something distasteful – weird growths on trees, for example, or noisome skin infections. In fact, as Merlin Sheldrake reveals in Entangled Life (Bodley Head, £20; Tablet price £18), fungi are one of the most remarkable elements in the biosphere, a vital factor in the development of plant and animal life, as well as providing mankind with such essentials as bread, penicillin and alcohol.