This Monday was full of grey light and low hanging cloud, and after a morning of open-weather meetings, I found myself sitting in the middle of Hackney Downs, happy to be listening to the sound of a satellite but craving some colour. On my way back from the park, a bright burst of lichen caught my eye. I identified the species (or 'collaboration' between species) as within the family of Teloschistaceae which really refers to a large group of mostly lichen-forming fungi that have a 'cosmopolitan distribution' (meaning that they can be found in most places around the world, much like the pigeon and the orca). Most members of Teloschistaceae are lichens that either live on rock or on bark, but about 40 species are 'lichenicolous' – meaning they are non-lichenised fungi that live on other lichens. Apparently, in Spain, a member of this family of lichen-forming fungi has been included in wine-based decoctions for menstrual issues, and infused in water as a remedy for kidney and tooth ailments. Later in the day, I bought raspberries and blueberries entirely because of how they glowed bright-red and blue-purple in the fruit section of the local market.