Bot 111

• Botany


  Scientific study of plants
• Morphology


  Study of external structure or form of plants and plant organs
• Anatomy


  Study of internal construction, including the organization and development at the cellular and tissue level
• Taxonomy


  A science that deals with naming, describing and classification of all living organisms including plants; subdiscipline under systematics
• Taxonomy introduced by A.P de Candolle in his Theorie elemntaire de la botanique

  1813
• Taxonomy

  Greek "taxis" – arrangement; "nomia" – method
• Two definitions of taxonomy

  • Theory and practive of grouping individual into species, arranging species into larger groups, and giving those group names, thus producing a classification (Judd, 2007)
  • The description, identification, naming, and classification of groups of organisms (Simpson, 2010)
• Naming and classifying our surroundings has taken place since mankind can communicate
• Humans are natural-born "taxonomists"
• Importance of plants are recognized since ancient times
• Earliest listing of plants are for recording their medicinal properties
• Examples of early civilizations who recorded the use of plants to cure human ailments

  • Chinese
  • Egyptians
  • Babylonians
  • Sumerians
  • Greeks
  • Romans
  • Aztec
  • Mayans
• Egyptians recorded their knowledge on temple walls and in the Ebers papyrus (1550 BC), which contains 700 medicinal formulas
• "The History of Plants" / "Historia Plantarum"


  Considered to be the oldest botanical work in existence, 350 bc - 287 BC, by Theophrastus, Father of Botany, successor to Aristotle
• Theophrastus observed 500 plants found in Greece and employed a holistic approach, describing each plant based on morphology, life cycle, and plant habit
• Theophrastus organized plants based on plant habit: tree, shrub, undershrub, and herbs
• Artificial system of classification

  Purpose: ease of identification, using a single or a few characters chosen arbitrarily, based on random choice or personal whim, rather than any reason or system, main criterion used was plant habit
• "De Materia Medica"


  Prime historical source of information about the medicines used by the Greeks, Romans, and other cultures of antiquity, classified 600 plants based on utility to mankind, groupings: aromatic plants, vegetables, and medicinal plants "herbals"
• Dioscorides' system was used in books about herbs until the 16th century
• Europe and Asia witnessed wars, famine, and epidemics during the "Dark Ages" (5th - 15th century)
• The "Renaissance period" (15th and 16th century) witnessed a renewed interest in plants and system of classification as more plants are being discovered and studied
• Examples of Botanists

  • Andrea Caesalpino (1519 - 1603), habit, structure of fruits and seeds
  • John Ray (1672 - 1705), habit (herbs, trees), dicotyledons and monocotyledons
  • Carolus Linnaeus / Carl von Linne (1707 - 1778), father of taxonomy, dominated botanical thinking in the 18th century
• Carolus Linnaeus' contributions

  Binomial nomenclature for naming organism, Linnaean system of hierarchical classification – rank based classification
• In binomial nomenclature, a species is given a formal name
• "Species Plantarum" (The Kinds of Plants) 1753 by Linnaeus – starting point for modern botanical nomenclature, 7,700 species of plants
• Linnaeus classified plants based on reproductive structures (sexual basis / sexual system of classification), divided flowering plants into 24 classes based on characteristics of stamen
• Examples of Linnaeus' classes

  • Class Monandria – "One husband in marriage" / all flowers with one stamen
  • Class Diandria – "Two husbands in the same marriage" / all flowers with two stamen
  • Class Monandria, Order Polygynia – "One husband, several wives" / all flowers with one stamen and several pistils
• Binomial nomenclature


  Each species is described in Latin by a sentence limited to 12 words (polynomials) or a shorthand description consisting of only 2 terms (binomial) - generic name and specific epithet
• Counterpart for animals: "Systema Naturae, 10th edition / 1758, starting point of zoological nomenclature, 4,400 species of animals
• Importance of binomial system of nomenclature

  Use of scientific name allowed people throughout the world to communicate unambiguously about a plant species – one universal name, ease of use, saves space, and time – shorthand binomial
• Linnaues' hierarchy of categories

  All known organism are placed into a logical classification based on similarities in morphological characteristics, Hierarchical (rank-based) classification, all things can be grouped into 3 great groups – kingdoms
• 3 kingdoms

  • Ragnum Animale / Animal Kingdom, Ragnum Vegetabile / Vegetable Kingdom, Ragnum Lapideum / Minerals; non-living things
• Linnaean hierarchy

  • Kingdom -> Phylum -> Class -> Order -> Family -> Genus -> Species
• Linnaean system was widely accepted in the 19th century, hierarchical approach / groupings organisms from least to most inclusive rank remains, classification changed over time
• Aristotle (384 - 322 BC) proposed the idea of Scala naturae / "ladder of being", where species are fixed or unchanging and can be arranged according to increasing complexity, connected with the ideas of Creationism
• Carolus Linnaeus observed similarities among the organisms and attributed to the wonders of creation, each species designed to serve a purpose, classification system – "filling in the steps of the ladder (of being)"
• Charles Darwin's On the Origin of Species was published, Theory of Evolution became increasingly accepted and changed the way the science of taxonomy was viewed and practiced


  1859
• Biological Evolution

  All life on Earth share a common ancestor, through the process of descent with modification – evolution, the common ancestor of life on Earth gave rise to the diversity of life today and in the past as documented in the fossil record
• Darwin's interpretation about how life on Earth began

  History of life is like a tree with branches representing life's diversity, organisms that belong to a branch of the tree are more closely related
• Natural selection


  Process in which individuals with favorable inherited traits are more likely to survive and reproduce, evolution happens when populations of organisms with inherited variations are exposed to environmental factors that favor the reproductive success of some individiuals over others, editing mechanism – it does not create new traits, results in evolution based on adaptations