Mycelium Magic?

 More often than not, when you see a group of mushrooms (fungi caps) they are connected by a thin underground membrane called a mycelium.  It's especially easy to visualize such a thing when you see the mushroom caps arranged in a circle and known as a Fairy Ring.  But I've heard of mycelia covering an area of thousands of square miles.  Imagine all the mushrooms of a given species in a particular state or region being essentially a single organism.  Creepy or wonderful, depending on how much science fiction you've read.

 I found these clusters on opposite sides of a building on campus, separated by at least 50 feet.  I couldn't help but wonder if they are connected, and maybe lived here before the buildings were erected.