As a city grows and its landscapes and habitats change from streams and forests and meadows to pavement and buildings and alleyways, what grows under the ground and on the ground changes. And those changes can be tracked by looking at old records – including books and articles and museum collections – to discover differences between then and now in the flora (the plants that grow there), the fauna (the animals that live there), the mycota (the fungi that live and grow there), and other biota (the biological organisms that are there), too.
Philadelphia, with its long history of natural history, is an uncommon place in this regard, when it comes to tracking down records of what was here before – including the mycota: https://fundis.org/resources/blog/120-rediscovering-philadelphia-s-1890-s-fungi-namp-project
Growing History 