Saturday, June 15, 2013

Labor of lichen love

I own a fair number of field guides and books about natural history, and as far as I know there has never been another book quite like Lichens of North America, by Brodo, Sharnoff, and Sharnoff (BSS). What exactly is this beautiful thing? It contains detailed descriptions, photos, and identification keys for more than 1000 species, yet weighing in at just under 9 pounds (!) it is strictly infeasible as a field guide unless you have a mule to pack it around for you. As a guide, then, it lends itself to collecting specimens and examining them at home-- and since fairly simple chemical tests seem crucial to identification in many cases, this is how it would often be used anyway. Needless to say, collecting is often to be discouraged, especially given our relative ignorance about the conservation status of lichens. BSS are careful to discuss these issues in their introductory chapters.

The photos, taken almost entirely by the Sharnoffs, are simply stunning. It is mindboggling to contemplate the time, travel, and sheer persistence that went into locating, identifying, and photographing every damn lichen in the book. The heft, page count, and beauty of the photos, drawings, and design cry out "coffee table"... but then, how many folks will allow the lowly lichens to displace their Monet at Giverny, or Earth from Above?

Lichens, as I hope you recall from grade-school science class, are actually the symbiotic relationship between two organisms, a fungus and an alga. I learned something new in the intro, which is that lichens did not evolve from a common ancestor, and therefore "cannot be considered collectively as a single branch on the evolutionary tree" (p. 4). Lichens are also considered useful canaries in the coal mine, given their sensitivity to air pollution. Now that we know that 90% of the human biome consists of "non-human" cells, many of which seem critical to good health, we may have more in common with the humble, symbiotic lichens than we thought.

$107 at Amazon, and worth every penny!

Arctoparmelia centrifuga, from Stephen Sharnoff's web site:


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