At least, I think it's a lichen. I'm pretty much of a neophyte to the technical side of lichens, though I have admired them for decades now. This one is eking out an existence in a 1-inch hole in the middle of a busy sidewalk near my home in the central valley north of Sacramento. Took a closeup photo yesterday while the sun was out, during a break in this unusually rainy winter. If someone could tell me its name, I would like to learn more about it.
Check this site: http://www.lichen.com/portraits.html On this site, they also advertise the book of lichens if you can find it in the library.
Thanks for the link, but I didn't find a single one that even came close. So, perhaps that means that it isn't a lichen?
Not necessarily. The book refers 805 lichen species, whereas this site only shows pictures for less than a hundred.
