How the surprising union between a fungus and an alga raises questions about the nature of identity

Elizabeth Lopatto in Bay Nature:

ScreenHunter_1812 Mar. 26 19.07In July, Governor Jerry Brown signed into law a bill declaring the lace lichen—found along the Pacific coast and throughout the coast ranges—the state lichen. As of January 1, 2016, California will be the first state ever to designate a lichen as a state symbol.

Lace lichen, Ramalina menziesii, is easily recognized. It is pale green and dangles in strips from trees. It’s sometimes confused with Old Man’s Beard (Usnea sp.), which is also pale green and dangly. Lace lichen’s range stretches from Alaska to Baja California. It’s an important food for deer; it also serves as material for birds’ nests. I see it once, in researching this story, when naturalist Morgan Evans, a former student naturalist aide at Tilden Nature Area in the East Bay hills, removes it from her backpack and spreads it out. Evans is a pleasant and patient woman, whose true love is fungi. Her interest in lichens is an extension of that, she says. Anyway, she found some lace lichen growing in Morgan Territory Regional Park. She figured I’d want to see it and there isn’t much growing in Tilden that she knows of. She hands me the lichen, which feels strangely plasticine. It’s pale green—she wetted it so it wouldn’t crumble when she transported it—and dangles impressively, at least six inches long. Lace lichen can grow as long as a meter, and it has a netted structure that looks, to me at least, more like fishnet stockings than lace. Perhaps fishnet-stocking lichen would be a little too racy a nickname.

Before I tell you more, though, a disclaimer: It turns out lichen identity is fraught with existential issues, not least of which is that lichens are a union between two separate organisms.

More here.