Integrative Biology 335 — Botanical Nomenclature

Announcements:

Your first take-home lecture assignment, worth up to 2% of your final grade, is due in class on Wednesday, February 11th. This assignment will be distributed in lecture today, or you may print out a copy of this assignment at this link if you've missed lecture. Penalties will be assessed for assignments handed in late (i.e., after class); assignments more than 24 hours late will not be graded. Answers will be posted on the web immediately after lecture the day they are due. Graded assignments will be returned to you in lab.

General Objectives:

After studying this material you should be able to:

1. Know the differences between common and scientific names, and the problems in using the former

2. Explain the four principles of botanical nomenclature covered this term, as outlined by the ICBN

3. Pronounce scientific names properly, with no silent "e" at the end of a word

4. Properly use the binomial system of naming species, as outlined by Linnaeus, which consists of the name of the genus, the specific epithet, and the taxonomic authority; in addition, you should know how to correctly write (or print) a scientific name

5. Describe and know how to use the three subspecific ranks for plants, and know what they mean biologically. You should also know the proper construction of these names and that trinomials (without indication of rank) should never be used

6. Know how to recognize the name of an interspecific hybrid and the two ways in which these names can be written

7. Recognize and construct names of cultivated plants

8. Be aware that alternative names exist for six families of flowering plants that we will study this term

9. Recognize incorrectly constructed scientific names and know how to fix 'em

Text and Other Resources:

• Plant Systematics, A Phylogenetic Approach by Judd et al., Third edition, Appendix One, Botanical Nomenclature, read relevant material on pp. 543 – 552. This is required reading.

• Download a reading by Dr. Ken Robertson as a pdf file. This short article provides a nice review of much of the information covered in today's lecture. This is required reading.

no-men-clature

There are two types of names for plants:

• common names — in a modern language, used in everyday conversation (some also made up for use in field guides)

• scientific names — in Latin or Latinized form, used for scientific purposes

COMMON NAMES

• In the language of the country or region. All of these common names refer to beech trees — beech (English); hêtre (French); haya (Spanish); faia (Portuguese); Buche (German)
• Uses familiar words
• The names by which most people know plants
• Can be stable within a region
• But, same common name can refer to more than one species in different regions (e.g., "bluebell" or "cedar") or the same species can have different common names in the same region
• Many species have no common names, especially if they are of little importance
• Common names are not standardized for plants

• “Mayflower” could be Maianthemum canadense or Epigaea repens

  -

• “Corn” in the United States is Zea mays, but in Europe “corn” refers to any kind of grain, while Zea mays is called “maize”

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The same plant can also have different common names:

• Hedge apple, Osage orange, bowwood, bois -d’arc all are used for Maclura pomifera

Common names can indicate that plants are related:

• White oak = Quercus alba, a true oak, as is
  
• Bur oak = Quercus macrocarpa

But common names can also be misleading:

• Poison-oak = Rhus toxicodendron or Rhus diversilobum, relatives of poison ivy, not related at all to oaks (Quercus)

Notice how many common names have two names (e.g., white oak, bur oak)

Scientific Names and the International Code of Botanical Nomenclature

The naming of plants is covered by the International Code of Botanical Nomenclature, a new edition is published after each International Botanical Congress; the current code is the “Vienna Code,” published in 2006. The following is in the Preamble to the Code — “Botany requires a precise and simple system of nomenclature used by botanists in all countries…The purpose of giving a name to a taxonomic group is not to indicate its characters or history, but to supply a means of referring to it and to indicate its taxonomic rank.”

The major goal of the ICBN is to provide one correct name for each taxonomic group (taxon) within a stable system of names (a classification)

The text of the Vienna Code, online listing the principles and rules of naming plants

The Principles of Botanical Nomenclature

• Botanical nomenclature is independent of zoological and bacteriological nomenclature.

• The nomenclature of a taxonomic group is based upon priority of publication. Priority begins with the publication of Linnaeus' Species Plantarum, published 1 May 1753.

• Each taxonomic group with a particular circumscription, position, and rank can bear only one correct name, the earliest that is in accordance with the Rules, except in specified cases. [For example, the correct name of a species is the combination of the earliest generic name with the earliest specific epithet, according to the Rules.]

• Scientific names of taxonomic groups are treated as Latin regardless of their derivation.

We are NOT emphasizing the following principles this year:

• The application of names of taxonomic groups is determined by means of nomenclatural types.
• The Rules of nomenclature are retroactive unless expressly limited. To avoid the disadvantages of a strict application of priority, the International Botanical Congresses have authorized the CONSERVATION of widely used family, generic, and species names, even though these names are NOT the oldest names.

Pronunciation of Botanical Names:

Names of genera identical to English common name:

• Chrysanthemum
  
• Geranium
  
• Rhododendron
  
• Magnolia
  
• Aster
  
• Catalpa
  
• Phlox
  
• Iris
  

Names of genera similar to English common name:

• Lilium — Lily
  
• Rosa — Rose
  
• Ulmus — Elm
  
• Populus — Poplar
  

However, the names of many genera may be unfamiliar:

• Jacquemontia
• Sisyrinchium
• Scheuchzeria
• Perideridia
• Eryngium
• Tiquilia
• Ipomopsis
• Tarasa

Guide to pronunciation of a few genera:

• Liatris — li-a'-tris
  
• Ribes — ri'-bes
  
• Actaea — ac-te'-a
  
• Acer — a'-cer
  
• Eleusine — el- oo'-si-ne
  
• Glycine — gli-cee'-nee
  
• Androsace — an-dro'-sa-ce
  
• Aloë — al-o'-e; pronounced al'-o in English
  
• Protea — pro-te'-a; pronounced pro'-te-a in English

• Desmanthus illinoensis
  
  • des-man'-thus
    
  • il-i-no-en'-sis
    

Note: Don't worry about mispronouncing scientific names! It is difficult to pronounce them incorrectly because there is no universally agreed upon system for pronouncing them! :) Just remember one point though, there are no silent letters at the end of a word (e.g., the "e" at the end of a word is pronounced).

Meanings of Latin Names

GENERA:

• Bauhinia — two brothers

  

• Commelina — three brothers

  

• Tillandsia — Tillands “by land” Map

  -

• Clarkia — for William Clark

• Lewisia — for Meriwether Lewis

• Andromeda, Cassandra, Cassiope, Leucothoë, Phyllodoce, Pieris — Greek mythology

  

• Harrimanella — Edward Harriman, railroad tycoon

• Theobroma — Food of the Gods

  

• Cornus — ancient name, also a horn

  

• Echinacea — hedgehog or sea urchin

  -

• Rosa carolina — from Carolina ( Carolina was a big area back then)

• Maianthemum canadense — from Canada

• Acer japonicum — from Japan

• Acacia melanoxylon — black wood

• Acer carpinifolium — leaves like Carpinus

  

• Acer palmatum — palmately lobed leaves

  

• Acer rubrum — red

  

• Acer saccharum — sugar

  

See textbook by Judd et al., Appendix 1, pages 544–545 for more meanings of Latin names

Scientific Names of Species:

The scientific names of species were originally descriptive phrase polynomials, such as Rosa carolina fragrans, foliis medio tenus serratis. These names were long and difficult to remember.

In 1753, Carolus Linnaeus in his Species Plantarum first consistently used binomial names for plants. This system still used today. The idea of two words as names is also common in English, as white oak.

Species Plantarum by Carolus Linnaeus

The BINOMIAL SYSTEM is used for the names of species. The SCIENTIFIC NAME of a species is the combination of the name of the genus with the specific epithet. To be complete, the scientific name includes the AUTHORITY or person who first described the species.

Genus	Specific epithet	Authority
Rosa	carolina	Linnaeus
Quercus	velutina	Lamarck

• The plural of genus is GENERA.
• The word SPECIES is both singular and plural.
• The name of the genus and the specific epithet are EITHER underlined or italicized.
• The authority is never underlined or italicized.
• The name of a genus is always capitalized. The names of genera are treated as nouns.
• It is always correct to write the specific epithet in all lower case. [Species named after people and after old generic names may be capitalized, i.e., Quercus Shumardii, Lindera Benzoin, but the ICBN recommends against it.]
• The specific epithet is usually considered to be an adjective that modifies the genus (noun), and it agrees in gender with the genus. E.g., Rosa rubrifolia, Rubus odoratus, and Quercus alba.
• When several species of one genus are given in sequence, the name of the genus can be abbreviated to its first letter. Crataegus phaenopyrum, C. mollis, C. pruinosa, C. viridis
• The authority can be abbreviated to save space, especially for authors who described a large number of species. The author’s name is never italicized or underlined. Crataegus viridis Linnaeus = C. viridis L.
• There may be joint authors, such as: Crataegus berberifolia Torrey & Gray. These may also be abbreviated, i.e., C . berberifolia T. & G. There is a standardized list of author abbreviations.
• When a genus, species, or subspecies is described at one rank and then transferred to another rank, the original author is placed in parentheses followed by the author who made the transfer. Rosa carolina var. villosa (Best) Rehder

Subspecific Ranks

For morphologically variable species, other ranks are applied.

The Code of Nomenclature recognizes the following SUBSPECIFIC RANKS as part of the taxonomic hierarchy: subspecies, variety, form. Not all species have subspecific taxa. It is permissible to use a lower subspecific rank without a higher subspecific rank.

Species
Subspecies (subsp.) — a geographical race
Variety (var.) — a local or ecological race (but sometimes a geographical race)
Form (f.) — a minor genetic variant that is mixed with other variants

The names of SUBSPECIFIC RANKS consist of the name of the species followed by an abbreviation of the rank, the subspecific epithet, and the authority for the subspecific name.

The subspecific epithet(s) must also be underlined or italicized.

SOME EXAMPLES:

Phlox pilosa (map)
Phlox pilosa subsp. pilosa
Phlox pilosa subsp. sangamonensis (map)

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Prunus lusitanica
Prunus lusitanica subsp. hixa

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Spiraea latifolia
Spiraea latifolia var. septentrionalis

-

Rhus aromatica
Rhus aromatica var. arenaria

Echinacea pallida
Echinacea pallida f. albida

Cercis canadensis f. alba

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Hybrids

HYBRIDS between two species in the same genus are indicated with the "×" [multiplication] sign and may be written in two forms:

1. Quercus alba × Q . michauxii [Indicates the species involved in the hybrid, in this case white oak crossed with swamp chestnut oak.]

2. Quercus × beadlei [Treats the hybrid as a species and gives it its own epithet.]

The cultivated strawberry is a hybrid of these species:

• Fragaria virginiana — Wild strawberry of eastern North America
  
• Fragaria chiloensis — Wild strawberry of western North America and South America.

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This hybrid may be written two ways:

1. Fragaria chiloensis × F. virginiana
   
2. Fragaria × ananassa

   

The common Vanhoutte or Bridal Wearth Spirea is a hybrid between two Asian species. The hybrid may be written two ways:

1. Spiraea cantoniensis × S. triloba
   
2. Spiraea × vanhouttei

   

Hybrids between species of different genera may also be designated accordingly.

Cultivated Plants

The name of a cultivated variety is given the rank of CULTIVAR, which have arisen from plants in cultivation. Some cultivars are propagated vegetatively, other are F1 hybrids. The application of such names is covered by the International Code of Nomenclature for Cultivated Plants (ICNCP).

The ICNCP, online

Do not confuse cultivars (meaning cultivated variety in earlier literature) with botanical varieties, which usually represent naturally occurring local or ecological races.

The cultivar name MUST be:

• preceded by the letters cv. or included in single quotation marks

• written in plain text, not underlined or italicized

• treated as ‘fancy’ names in a modern language. NEW cultivar names cannot be in Latin and may not be the same as the botanical or common name of a genus.

• Capitalized

The rank of cultivar is NOT in the subspecific hierarchy, but may be used with any taxon from genus downward.

Some examples:

Cercis canadensis ‘Forest Pansy’

or

Cercis canadensis cv. Forest Pansy

Tilia tomentosa ‘Ster£ing’

or

Tilia tomentosa cv. Ster£ing

Liquidambar styraciflua ‘Autumn Enchantment’

or

Liquidambar styraciflua cv. Autumn Enchantment

Pyrus calleryana ‘Bradford’ or

Pyrus calleryana cv. Bradford

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Malus domestica ‘Red Delicious’, ‘Golden Delicious’, and ‘Jonathan’

or

Malus domestica cv. Red Delicious, cv. Golden Delicious, and cv. Jonathan

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Sorbus ‘Joseph Rock’

or

Sorbus cv. Joseph Rock

Rosa ‘Peace’

or

Rosa cv. Peace

Fagus sylvatica ‘Pendula’

or

Fagus sylvatica cv. Pendula

Magnolia × soulangeana ‘André LeRoy’

or

Magnolia × soulangeana cv. André LeRoy

The use of Trademarked and Plant Patent names is complicated and we will not mention them further in this class. For more information, see <http://www.plantdelights.com/Tony/trademark.html> and <http://www.plantpatent.com/articles.html>.

Your questions answered ...

This is from an e-mail sent by a student who took this class previously:

“It might be a good idea to explain the differences in scientific nomenclature. I know even in herbaceous perennials/annuals, the names I learned have changed, like with Chrysanthemum going to Dendranthemum, and Coleus just changed to something else [Solenostemon], as well as Vinca major going to Catharanthus roseus, and the list goes on. So I do feel it would be good for us know the reasons why names are changing.”

Good question! The International Code of Botanical Nomenclature says that “Each taxonomic group with a particular circumscription, position, and rank can bear only one correct name, the earliest that is in accordance with the Rules …” There are several reasons why you see different publications using different scientific names for the same species.

• One reason is that there has been a name change made necessary by the rules of the Code. Often, this means that someone finds a name that was published earlier than the name currently used.

• A second reason is that some groups of plants are more difficult to classify than others, and different authors may classify them differently.

• Another reason is that new systematic data (such as that obtained from DNA sequencing) or a reevaluation of traditional data that has been rigorously analysed using a phylogenetic approach may indicate that two groups formerly considered related to each other, and thus placed in the same genus or family, may not be related at all. Increased knowledge about a species' phylogenetic relationships results in a change in its name. Species can be transferred to different genera, and the circumscriptions of genera and families may be quite different from their traditional delimitations.

• For further information on this topic, see your textbook (Appendix One, p. 546).

Alternative Family Names

The Code of Botanical Nomenclature says that family names are based on the name of an included genus. However, there are a few traditional family names that MAY still be used as alternatives to those names ending in –aceae. Below are 7 common examples.

• Apiaceae — Umbelliferae — Umbel family
• Arecaceae — Palmae — Palm family
• Asteraceae — Compositae — Sunflower family
• Brassicaceae — Cruciferae — Mustard family
• Fabaceae — Leguminosae — Bean family
• Lamiaceae — Labiatae — Mint family
• Poaceae — Gramineae — Grass family

What is wrong with these names?

Malus baccata mandschurica

Phlox var. amplexicaulis

Gleditsia triacanthos ‘inermis’

Gleditsia Sunburst

Tilia cordata cv. greenspire

Genus: Diomedea
Species: amsterdamensis

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