Day 33: Collectively known as "wax-paper lichens," the Parmelias are characterized by a surface which resembles that of crinkled wax paper. To differentiate certain of them in the field (some require chemical testing), it may be necessary to observe the rhizines (root-like structures) on the backs of the lobes, and one should observe the ridges and cracks closely (preferably with a hand lens) for the development of soredia (asexual reproductive structures). Although I was fairly certain that both of the specimens I was examining were Parmelia sulcata despite the fact that one was distinctly long in the soredia department, I took a small sample of each one (of a size smaller than the pink of my little fingernail), dropped them in one of the test tubes I always carry in my bag, and checked them under the microscope when I got home. Yup, both sulcata. And for those of you who might be interested, the term "sulcata" means "furrowed." Knowing that will make remembering the characteristics of this lichen a bit easier.
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