Plant Taxonomy (BIOL308) - Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321; ssaupe@csbsju.edu; http://www.employees.csbsju.edu/ssaupe/ |
NOMENCLATURE
"Must a name mean something?
I. Definition
System by which plants are named. Or a more fancy definition -
determining the correct name of a plant according to a nomenclatural system.
II. Why name organisms?
Lewis Carroll knew the answer. Remember Alice's encounter with
the Gnat in Through the Looking Glass?
"What sort of insects do you rejoice in, where you come from?" the Gnat inquired.
"I dont rejoice in insects at all," Alice explained, because Im rather afraid of them - at least the large kinds. But I can tell you the names of some of them".
"Of course they answer to their names?" the Gnat remarked carelessly.
"I never knew them do it."
"Whats the use of their having names," the Gnat said, "if they wont answer to them?"
"No use to them," said Alice; "but its useful to the people that name them, I suppose. If not, why do things have names at all?"
"I cant say," the Gnat replied.
Answer (take-home-lesson): "it's useful to the people that name them". Nature doesn't give organisms names, humans do for utilitarian purposes to communicate information about organisms.
Plants "answer" to their names in the sense that a name provides a way to communicate information. Tippo and Stearn (1977) consider names to be "...indispensable guides to the order of any realm. Names are abbreviated histories, they have dimension in time; they are the beginning points of classification, the designations by which things are known. These are some of what is in a name".
Imagine how chaotic life would be without names. Remember Alice's adventures in the nameless woods, where nothing had a name...?
"This must be the wood, " she said thoughtfully to herself, "where things have no names. I wonder whatll become of my name when I go in? I shouldnt like to lose it at all - because theyd have to give me another, and it would almost certain to be an ugly one. But then the fun would be, trying to find the creature that had got my old name! Thats just like the advertisements, you know, when people lose dogs - answers to the name of Dash, had on a bass collar - just fancy calling everything you met Alice, till one of them answered! Only they wouldnt answer at all, if they were wise."
And Alice continued her philosophical discussions....
"I suppose you dont want to lose your name?"
"No, indeed," Alice said, a little anxiously.
"And yet I dont know," the Gnat went on in a careless tone: "only think how convenient it would be if you could manage to go home without it! For instance, if the governess wanted to call you to your lessons, she would call out "Come here ____," and there she would have to leave off, because there wouldnt be any name for her to call, and of course you wouldnt have to go, you know".
"That would never do, Im sure," said Alice: "the governess would never think of excusing me lessons for that."
Even Shakespeare has considered the importance of a name (from Romeo and Juliet):
"tis but thy name this is my enemy;
Thou art thyself, though not a Montague.
What's a Montague? it is nor hand, nor foot,
Nor arm, nor face, nor any other part
Belonging to a man. O! be some other name:
What's in a name? that which we call a rose
By any other name would smell as sweet;
So Romeo would, were he not Romeo call'd.
III. Common (or non-technical or vernacular or folk) Names
A. Advantages. Common names have the following advantages:
B. Disadvantages. If common names have so many advantages, then why bother with scientific (or technical) names? Because of the disadvantages, and there are some major ones. Common names:
Take-home-lesson: scientific names are preferred because they are exact, the same the world around, and governed by rules. And, as we'll learn later, scientific names also reflect the classification system, and hence the evolutionary relationships of the plants.
C. Common Names Can Matter, or What is Wild Rice?
Zizania palustris is the
scientific name for 'wild rice', which is native to lakes and rivers of Minnesota and the
upper Midwest. The Ojibway, who called this plant "manoomin", have long
harvested the grain and have sold it as a specialty food. Until relatively recently, all
commercially-available wild rice was harvested from wild plants using traditional methods.
However, in the late 1960's wild rice was 'tamed' and most is now grown in paddies,
ironically, largely in California. So, what should this domesticated version of wild rice
be called? Many think that 'wild rice' should be restricted to wild-grown grains,
especially by many Ojibway who contend that wild-grown rice tastes much better than paddy
grown rice. And, not long ago I made a trip to New Zealand and packed several pounds of
uniquely Minnesota-style gifts for my friends. The NZ Customs went "wild" when I
declared that I was in possession of wild rice and they confiscated all of it,
even though it was precooked. For more
information check out the article by Walsh (1998).
D. Good News.
In a few cases, if you know the common names you are the same
as the genus names. For example: Iris, T.
rex, Asparagus, Begonia, Canna, Catalpa, Euonymus, Forsythia, Ginkgo,
Magnolia, Petunia, Phlox, Rhododendron, Sassafras, Verbena, and Viburnum (thanks
to Dr. David Hershey for many of these suggestions).
IV. The Rules - Scientific Names
A. The Rule Book
The rule book for botanical nomenclature is the International Code of Botanical
Nomenclature (ICBN). It is updated periodically at the International Botanical Congresses.
The most recent was held in St. Louis in 1999 and an electronic version (called
the St.
Louis Code) is available. The previous conference was held in
Tokyo in 1993 (the Tokyo
Code is also available on-line). Print versions are also
available and are color-coded: purple (Tokyo, 1994), yellow (Berlin, 1988),
green (Sydney), red (Leningrad).
B. Some Rules.
Generic names are typically: (a) singular nouns; (b) often descriptive (i.e., relative to habit, habitat, geography, growth, morphology. For example, Liriodendron tulipifera - Lirio = tulip lily); (c) may be derived from other cultures/languages (i.e., Zea mays, Sassafras); (d) commemorate a person or place (i.e., Jeffersonia, Kalmia, Franklinia), except oneself.
Some genus names are taken directly from Latin (i.e., Acer - maple; Triticum - wheat). Some genus names are even derogatory. For example, Linnaeus named a small unattractive sunflower after a critic, Siegesbeck (Siegesbeckia).
The genus name is written with the first letter capitalized. It is italicized or underlined, and can stand alone (i.e., Quercus). The plural of genus is genera.
Abbreviations: spp. - more than one species in the genus; sp. one species where the specific species is not designated.
The specific epithet is typically an adjective that agrees in number and gender with the generic name. It can also be commemorative, descriptive, etc. The specific epithet is written all lower case (except for a few exceptions like some names commemorating a person). Note the specific epithet is always accompanied by the genus name; it cannot stand alone. For example, the specific epithet alba could refer to Quercus alba or Lychnis alba or even another plant.
Linnaeus is typically given credit for the binomial system. He didn't invent it, but he was the first to consistently use it in Species Plantarum (1753). This system was certainly an improvement over the previous polynomial system. However, these polynomials also served as the "description or diagnosis" of the plant. For example, the polynomial of the Briar rose (or Dog rose) was Rosa sylvestris alba cum rubre, folio glabro. This translates into "pinkish white woodland rose with smooth leaves" and was subsequently shortened to Rosa sylvestris (and then changed to Rosa canina).
A parenthetical authority refers to the original author of a name after it has been changed by someone else. For example, Linnaeus named what we know as a hemlock tree as Pinus canadensis. Carriere later recognized that it was a hemlock and not a pine, and transferred it to the genus Tsuga. Thus, the name is Tsuga canadensis (L.) Carr. Linnaeus, the original author, is the parenthetical authority, and Carriere, the new author of the name is the combining authority. Also note that the specific epithet "canadensis" is conserved and is called the basionym. It's somewhat similar to what happens when sports teams change cities - LA Lakers are originally from the Twin Cities and the Utah Jazz from New Orleans.
Common Name | Traditional Family Name | New Family Name |
Grass Family | Graminae | Poaceae |
Mustard Family | Cruciferae | Brassicaceae |
Mint Family | Labiatae | Lamiaceae |
Carrot Family | Umbelliferae | Apiaceae |
Sunflower Family | Compositae | Asteraceae |
Palm Family | Palmae | Arecacaceae |
Garcinia or St. John's Wort Family | Guttiferae | Clusiaceae |
A good example of the principle of priority is given in Stephen J. Gould's essay, "Bully for Brontosaurus". Apatosaurus is technically the correct name for this species because it was published first, although rather hastily, beating the name Brontosaurus into press. The rush to be the first to discover new specimens and name them has, in some cases like this, caused fierce scientific competition and even resulted in sloppy science and sometimes even a little "sleaziness" and back-stabbing. Another good example of the latter is described in Ott's (1976) book and in his rejoinder.
Type specimens didnt come into use until after the evolutionary paradigm developed. Under the older paradigm of "fixity of species", any specimen would be adequate. This practice was first adopted in the 1950's.
There are lots of other kinds of types (don't memorize these): lectotype - specimen selected from the original material to serve as type when the holotype was not designated or if it is missing; neotype - specimen selected to serve as the type when all material on which the name is based is missing; paratype - specimen cited in original description, other than holotype. See Frizzel (1933) for a discussion of additional kinds of type specimens. By the way, the CSB/SJU Herbarium has one isotype.
Kingdom | Division | Class | Order | Family | Genus | species |
Plantae | Magnoliophyta (angiosperms) | Magnoliopsida (eudicots) | Asterales | Asteraceae | Taraxacum | T. officinale |
There is a movement to create a uniform nomenclatural system for all organisms. This "BioCode" is rather controversial and meeting with some resistance in the botanical community because of the many changes that will result.
V. Botanists may have fun with scientific names
For example, translate the scientific
name of the Caribbean caper, Capparis cynophallophora (Greek kyon = dog; phallos =
penis; -phor = to bear). For a list of humorous scientific names, check
out the article by Milus (2001).
VI. Identifying a valid name
As described above, the correct name for a plant is the
oldest, validly published name. Although this sounds simple, in practice it can be
challenging to sort through all of the names that have been published for a species and
determine which is the correct one. Here's a few tips: (1) list all of the names that have
been published for the species in order of publication date; (2) Names with the same
specific epithet are usually based on the same type specimen and the latter
author knew about the work the work of the earlier author but disagrees with
him/her (i.e., nomenclatural
synonym; homotypic synonyms); (3) names with different specific epithets are based on
different types (i.e., taxonomic or heterotypic synonyms); (4) the oldest specific
epithet is conserved unless there is a reason to discard it. As mentioned above,
this is similar to the
situation in professional sports where the team name is conserved as the team changes
cities (i.e., L.A. Lakers); and (5) it may be necessary to form a new name (recombining).
VII. Pronouncing scientific names
Two simple rules are: (1) don't accent any syllable;
and (2) pronounce each letter. For additional rules and information check
out our text or Stearn's excellent book. The good news is that you can pronounce them however you
want.
VIII. Name changes
Although it may seem that botanists change scientific names just to
frustrate us, this is not the case. Names are changed because additional scientific study shows that the
original name: (1) didn't follow the rules (i.e., wasn't the
earliest, or is taxonomic or nomenclatural synonym) or (2) because our taxonomic ideas of
the genus and species has changed since the original study (i.e., additional studies
showed that two closely related species are actually one). Perhaps this is a good time to
mention taxonomists who are "splitters" (focus on the differences between taxa)
and those who are "lumpers" (focus on the similarities).
IX. Ethics of Naming
Sadly, racism has crept into even plant names. Consider
the following common names: Niggertoes (=Brazil nuts), Wandering Jew,
Coolie's cap, Kaffir lily (in fact, there are 75 South African plants have
kaffir in their name), Jew Bush, Pope's nose, and Digger pine (Pinus
sabiniana). Digger pine, native to California, was named as a slur on
the natives who "dug" for roots. Fortunately, we can avoid using
these common names. In fact, Dr. David Hershey reports that in the USDA
Plants Database, digger pine has been replaced by California foothill pine. However, what do we do if the racist word is part of
the scientific name, as in Erythrina caffra (Fabaceae)? It is
more difficult to expunge these names since they follow the current
"rules."
Another interesting example comes from an article in The Week (March 18, 2005) that reported that the Turkish government was renaming three native animals to remove references to Kurdistan and Armenia. This will be difficult since they want to replace scientific, not common, names.
X. References
Internet Sites
A. Course Lecture Notes
B. Databases
C. General
So out of the ground the Lord God formed every beast of the field and every bird of the air, and brought them to the man to see what he would call them; and whatever the man called every living creature, that was its name. The man gave names to all cattle, and to the birds of the air, and to every beast of the field
Genesis 2: 19, 20.
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Last updated:
09/11/2007 / � Copyright by SG
Saupe