Fungi challenge our traditional taxonomic system because their world is about processes and relationships, where one species can be almost indistinguishable from another. They can also look very different depending on the day. “You’re transported into a whole other world – it’s like Gulliver’s travels through a hand lens,” said Plantlife’s Dave Lamacraft. A five-year citizen science fungi conservation project run by Kew Gardens, which started in 2014, resulted in the discovery of species that had not been seen for up to 100 years. We need these records – we need these amateurs to be identifiers Prof Lynne Boddy Crystal brains and witches' butter: discover the fabulous world of fungi