Hypogymnia Physodes

Day 52: My fence is home to quite a variety of lichens, and calling to mind the cobbler's kids and their bare feet, I have to admit that I've never troubled myself to identify many of them. Generically, they're "fencepost lichens" in a hypothetical field guide to Crow's yard, a category which includes Usneas, Cladonias and Evernia, distinguished only by their attachment to cedar rails. I've never taken samples, never looked at potential identifying features until recently when I was prompted to do so by finding several of these small rosettes growing on the side of my house. Anything which can survive on a substrate of plastic is worthy of further study, so today I nicked a lobe and brought it indoors for examination. Thinking I had a fairly good idea where it belonged, I attempted to fit it into a family, but square peg that it was, it refused to go in the round hole. I don't know what compelled me to scrape at the dark underside with my thumbnail, but when I did so, it came away freely, revealing a white medullary ceiling. What? Waitaminit...it's a Hypogymnia! From the moment of that epiphany, the rest of the pieces fell neatly into place: Hypogymnia physodes, "one of the most common tree lichens in the north." Tree lichen, eh? Mine have a taste for vinyl siding.