I can't find any reference to this luxuriant black moss, here on granite boulders
at Acadia National Park. In large enough mats it has a shine. Is this really a moss?
Some sort of lichen? I did find out that some mosses, when fully exposed to direct sunlight
(as these surely are), produce more anthocyanins to protect themselves, turning black. So
these could be mosses that look very different in other locations.
Unknown 12 description by Thomas H. Kent, last updated 25 May 2020.