FBS 21 Lecture

• Biology requires a precise and simple system of nomenclature used by biologists in all countries, dealing on the one hand with the terms that denote the ranks of taxonomic groups or units, and on the other hand with the scientific names that are applied to the individual taxonomic groups of plants.
• the rules of name-giving, nomenclature, have nothing to do with Biology, but are more in the field of law.
• Nomenclature is the precise system that deals with terms indicating the ranks of taxonomic groups as well as the application of names to such groups. It is the study of the system and methods of naming organisms which includes construction, interpretation, and application of the regulations governing the system. The principles form the basis of the system of botanical nomenclature.
• The International Code of Botanical Nomenclature (ICBN) standardizes name of plants. ICBN is enacted by International Botanical Congress which meets every four years. It’s a law, and the enforcement of which is based on botanical agreement
• Nomenclatural type

  An element (usually an herbarium specimen) with which the name is permanently associated. It fixes a name to a particular taxon.
• Validly published name

  • Published in printed matter available internationally
  • Accompanied by a description or diagnosis, or reference to a previously published description
  • Accompanied by a Latin description or a reference to a previously and effectively published description or diagnosis
  • Indication of a nomenclatural type
• With a few exceptions, the correct name is the earliest legitimate name (name in accordance with all the rules of the code)
• Rule of priority is not mandatory above the rank of the family
• Species Plantarum was established

  May 01, 1753
• Commonname or vernacular name is not accepted in ICBN
• Reasons why commonname or vernacular name is not accepted in ICBN

  • Multiplicity of language and use of different alphabets
  • The same name is often used in different sense to denote different species
  • One species may be known for more than one name
• Species names must be in Latin form written in Latin alphabet and subject to the rule of Latin grammar
• Why in Latin?

  • Latin is a dead language, it is no longer used therefore very conservative, and more or less permanent
  • It is the common language of learned men in Europe where science of Botany originated and developed
  • Latin was the language used when Linnaeus developed the system of nomenclature
• Binomial


  The generic name and the specific epithet form the binomial called the scientific name
• Complete scientific name


  Includes the third element- the author who formally described the plant. The name of the author is often abbreviated.
• Monomials


  Names of taxa at the upper principal ranks above the species
• Trinomials


  Names at the infraspecific level
• Scientific names are usually italicized when in print and underlined when typed, hand written or printed
• Scientific names when used in manuscript is always enclosed in parenthesis
• The generic name is singular, Latinized noun or word treated as a noun. The initial letter of the generic name is always capitalized, the remainder in small letters e.g. Pterocarpus

  In manuscript, after the generic name has been spelled out once, the initial letter may be abbreviated subsequently.

  ex. Pterocarpus indicus L. in the next mentions of the name could be written as P. indicus

  All letters in the specific epithet are in the lower case. e.g. indicus

  Derivation of Names

  1. Commemorativenames–namesofpersonsareusedas,genericname

  or specific epithet, generally to honor a person.
• When the genus is named after a person

  1. If the name ends in a vowel, the letter a is added

  2. Except when the name ends in 'a', ea is added

  3. When the name ends in consonant, letter ia is added

  4. Except when the name ends in 'er' only a is added
• When the specific epithet is named after a person


  1. When name ends in a vowel, letter i is added

  2. Except when the name ends in 'a', e is added

  3. When name ends in a consonant letter, ii ia added
• Descriptive/Adjectival names - names that convey something characteristic about a particular species


  • Names relating to color
  • Names relating to direction
  • Names relating to Geography
  • Names relating to habit
  • Names relating to habitat
  • Names relating to seasons
  • Names relating to size
• littoralis


  of the seashore
• montana


  of the mountain
• vernalis


  pertaining to spring
• aestivus


  pertaining to summer
• Nominative names - old generic, common and aboriginal names

  • Vitex negundo
  • Zea mays
• Miscellaneous names - other characters or combination of characters

  • Dipterocarpus grandiflorus
  • Taxus baccatus
  • Artocarpus heterophyllus
• Gender agreement - Generic name and the epithet should have the same gender
• Masculine endings

  us

  er

  is

  i
• Feminine endings

  a

  ra

  is

  ris
• Neutral

  um

  rum

  e

  re
• Modifiers ending in –ans, -ens, -or, -x use only one ending for all genders. Example: Ranunculus repens; Ludwigia repens; Trifolium repens
• Types

  • Holotype
  • Isotype
  • Syntype
  • Lectotype
  • Isolectotype
  • Neotype
  • Boobootype
  • Kleptotype
• Holotype


  The one specimen or other element used by the author or designated by him as the nomenclatural type
• Isotype


  Duplicate of the holotype
• Syntype

  Two or more specimen designated by the author when no holotype was designated
• Lectotype


  One of the syntypes subsequently chosen to act as holotype
• Isolectotype


  Duplicate of lectotype