تصنيف

• When a person in the past collected and identified a plant as useful for food or fuel, this led to the development of the field of taxonomy
• As the number of known plants grew, there was a need for a systematic way to study and identify them
• Taxonomy


  The science that aims to study and classify living organisms in order to facilitate their identification
• Plant Taxonomy


  The branch of taxonomy that deals with the classification of plants
• Taxonomy


  The science that studies the classification of living organisms in order to facilitate their identification
• Systematic


  The study and description of the variations in living organisms and the search for the causes of these variations, in order to develop a taxonomic system
• Classical or Orthodox Taxonomy


  The traditional taxonomy that relies primarily on the study of morphological and anatomical characteristics
• Experimental Taxonomy or Biosystematics


  The modern taxonomy that relies on field studies and aims to reflect the evolutionary relationships between organisms
• The evolutionary relationships between taxonomic ranks are referred to as the phylogenetic system of classification
• Modern techniques used in taxonomy include serology, DNA sequencing, and PCR (Polymerase Chain Reaction)
• Objectives of Taxonomy


  • Identification
  • Nomenclature
• Identification


  Determining the identity of a plant by referring it to the taxonomic group (taxon) to which it belongs
• Methods of Identification


  • Comparison with specimens
  • Use of taxonomic keys
  • Personal communication with experts
• Nomenclature


  Assigning a new scientific name to a plant according to the International Code of Botanical Nomenclature (ICBN)
• Taxonomic Ranks


  • Kingdom
  • Division
  • Class
  • Order
  • Family
  • Tribe
  • Genus
  • Species
• مجلات


  • Brittonia, Taxon, American journal of Botany
• الحديقة النباتية أو حديقة التجارب


  Botanical (Experimental Garden)
• John Ray (1608 - 1705) اصطلاح دولپه اي ها و تك لپه اي ها را معرفي كرد
• Carolus Linnaeus سيستم دوگانه نامگذاري را پايه گذاري كرد
• Linnaeus


  The Father of Taxonomy
• Linnaeus' famous books


  • Systema Naturae
  • Genera Plantarum
  • Species Plantarum
• Linnaeus classified the plant kingdom into 24 classes based on characteristics such as length, number, and nature of attachment of sexual organs
• Linnaeus' division of plants

  • Vascular plants
  • Non-vascular plants
• Bentham and Hooker authored the famous book Genera Plantarum which focused on the classification of seed plants
• The idea of evolution spread after Darwin's work in 1859
• Classification systems


  • Mechanical/Artificial system
  • Natural system
  • Phylogenetic system
• Reliance on only external morphological features in classification can lead to errors due to environmental variations and similarities
• Quantitative characters are more variable than qualitative characters
• It is difficult to determine which features are primitive or advanced for a species
• Features used in plant classification


  • Cellular composition
  • Tissue system
  • Presence/absence of vascular tissues and flowers
  • Reproductive structures
  • Gross and micromorphology
• Twining plant


  Herbaceous or vine-like plants that require a support to climb, e.g. morning glory, convolvulus, dolichos
• Twig


  Short woody stem or branch of a woody plant, e.g. autumn branches of fig tree
• Scape


  Flower-bearing stem arising from the ground, as in dandelion and onion
• Cespitose plant


  Plant growing in dense tufts, as in many grasses
• Asses


  Family Gramineae
• Insectivorous plants


  • Utricularia (bladderwort)
  • Nepenthes (pitcher plant)
• Families of insectivorous plants


  • Lentibulariaceae
  • Droseraceae
  • Sarraceniaceae
  • Nepenthaceae
• Insectivorous plants are found in other regions of the world
• Scleroplytic plants


  Plants with semi-cartilaginous leaves, like oak (Quercus, Family Fagaceae) and juniper (Juniperus, gymnosperms)
• Succulent plants


  Plants with thick, fleshy and juicy stems and leaves, like Portulaca (Portulacaceae), many Aizoaceae, Chenopodiaceae, and Zygophyllaceae. Cactus is an example of a more succulent plant.