7 of 100: Binomial nomenclature

Up until this morning, I thought very little about binomi(n)al nomenclature—the system whereby living things are "specifically" identified using two names derived from Latin and Greek. Except that it's useful, and often entertaining.

The coast live oak outside my window? It's Quercus agrifolia, of course! From the Latin, meaning Oak + sharp-leaved. Named, no doubt, by the "father of taxonomy" Carl Linnaeus himself!

But then I started researching a lovely orchid I ran across on Facebook yesterday, Pogonia ophioglossoides, the snakemouth orchid, aka rose or fragrant pogonia (it smells like raspberries!). (At least, that's what I thought it was—but see below.) When I checked out its classification—kingdom, clade, order, family, subfamily, genus, species—I noticed that P. ophioglossoides is only its most recent name. It's had others, beginning, yes, with Linnaeus—Arethusa ophioglossoides L. (its "basonym")—and followed by A. parvifolia Michx. (André Michaux) and P. pendula Lindl. (John Lindley). The current name is followed by the designation Ker Gawl., standing, I learned, for the Englishman John Bellenden Ker (c. 1764–1842), an orchid specialist who published several books and described many species, including this one.

What's with all these names? And what about that coast live oak? Well, ha! At least its six synonyms all agree that it's in the genus Quercus, but beyond that, all bets are off. And, no surprise, Linnaeus apparently never even heard of this tree, otherwise wouldn't he have given it a name too?

This all took me down the rabbithole of nomenclature, beginning with binomialism itself, first formalized by Linnaeus in his 1753 publication Species Plantarum and extended to zoology in 1758 with his Systema Naturae, 10th ed. Clicking links took me to discussions of synonyms, which are treated differently in botany and zoology (I will spare you the details); botanical names, which must conform to International Codes of Nomenclature; the difference between botanical and zoological nomenclature (including that the latter may repeat terms—e.g., Bison bison—while the former may not). And so much more. 

Actually, I arrived at this topic by venturing one click away from P. ophioglossoides. I thought I'd take a look at orchids generally, to see how big a family it is. (Turns out it's one of the two largest families of flowering plants, with about 28,000 currently accepted species spread across 763 genera.) And there I saw this: Family Orchidaceae Juss.

And I thought, what is this Juss.? And where is L.?

That's how I fell down the rabbithole. Four simple letters—standing for Antoine Laurent de Jussieu (1748–1836), who was the first to publish a natural classification of flowering plants. "Natural" being the key word here, as opposed to Linnaeus's "artificial" system: whereas Linnaeus looked at just a few morphological characteristics, such as number of stamens and pistils, Jussieu took into account a greater number of traits, including how they are expressed among plants generally. As he put it, plant characteristics should be "pessés et non comptés"—weighed and not counted. He then organized plants into three different groups—acotyledons (having no distinct embryonic leaves, such as ferns and mosses), monocots (having one, such as garlic, coconut, wheat, and orchids), and dicots (having two—most flowering plants), which he further divided into 15 classes and 100 families.

That Juss.? It's included—along with hundreds of others, among them L., Michx., Lindl., and Ker Gawl.—on an "incomplete" (but still plenty long) list of botanists by author abbreviation. Now when I look at a list of synonyms/former names of specific species, I will undoubtedly see those designations, whereas until this morning I (apparently!) skipped right past them.

Incidentally, when I started researching this entry, I googled the name the photographer had used in his FB post, "fragrant pogonia," and ended up with the species discussed above. But I wondered why none of the Google photos included three long red streamers that I had found particularly winning in the FB shot. I went ahead and wrote the above, but those streamers niggled at me. So I went back to FB and searched again. And discovered that I'd gotten it wrong: yes, the person who posted the photo called it fragrant pogonia—that much I'd remembered correctly, though it's also called coastal plain pogonia; but the specific name was different: Cleistesiopsis oricamporum P.M.Br. (P.M.Br. standing for P. M. Brown, who originally published this species, in 2009, and who is not on the above list, proving that it is, indeed, incomplete). And right there you have the reason for binomial nomenclature, as opposed to "common" names (and I therefore celebrate my error as a case in point!). This specimen was photographed in 2016 by Roger Hammer in Apalachicola National Forest, Florida. Isn't it gorgeous? 

And now I've definitely rambled on long enough. I may return to binomialism later—I happen to enjoy parsing all those Greek/Latin names (Pogonia ophioglossoides, in case you were wondering—and I'm sure you were—means Beardlike + Snake-tongue), plus it's a huge, fascinating topic: how we parse our very world. And here I thought today I'd just learn a little something about a pretty pink orchid with a sweet smell!