reproductive morphology

• Flower


  Sexual reproductive structure of flowering plants
• Flower


  • 4 main parts: Sepals, Petals, Stamens, Pistils

  
• Sepals - Calyx


  Outermost whorl or part, usually green and photosynthetic, leaflike, cover and protect the more delicate tissues that are developing within the bud
• Petals - Corolla


  Often brightly colored, showy and conspicuous, broad, flat and thin, resemble leaves in their overall organization, may be photosynthetic, serve to attract insects

  
• Stamen - Androecium


  Pollen producing structure (male), anther and filament
• Pollen grains


  Male gametophyte, radially or bilaterally symmetrical bodies that represent units of dispersal from the anther to the stigma, wall: exine and intine, apertures: sulci and colpi
• Pistil - Gynoecium


  Central portion of flower (female), stigma, style, ovary, composed of one or more carpels

  
• Carpels


  • Monocarpous: one carpel per flower, Apocarpous: two or more distinct carpels, Syncarpous: carpels connate

  
• How to determine the number of carpels in a gynoecium

  1. Count the stigmas or stigmatic lobes

  2. Count the styles

  3. Count the lobes of the ovary

  4. Count the locules in the ovary

  5. Count rows of placentae
• Ovule


  Consist of a nucellus, which bears the embryo sac, enclosed by one or two integuments
• Nucellus


  Central portion of an ovule in which embryo sac develops; the megasporangium
• Embryo sac


  The megagametophyte, possesses eight nuclei arranged in seven cells
• Types of flowers according to presence/absence of flower parts

  • Complete: containing sepals, petals, stamens and at least one carpel/pistil
  • Incomplete: lacks one or more of the floral parts
  • Perfect: with both male and female parts
  • Imperfect: lacks one of the essential organs; either pistillate or staminate
• General arrangement of flower parts

  • Radial /actinomorphic symmetry: flower divisible on more than one axis into two equal halves that are mirror images of each other
  • Bilateral / zygomorphic symmetry: flower divisible into mirror images on only one axis
• Types of flowers according to position of ovary

  • Hypogynous flower: superior ovary; flower parts arise from a level below ovary base
  • Perigynous flower: semi-inferior ovary; flower parts attach halfway up the ovary
  • Epigynous flower: inferior ovary; flower parts arise from a level above ovary base
• Types of flowers according to position of complexity

  • Solitary /simple
  • Inflorescence: clusters of flowers; has one main stalk (peduncle); also bears numerous smaller stalks (pedicels) each with a flower at its tip

  
• Types of inflorescence


  • Panicle: a branched main axis with side branches bearing loose clusters of flowers
  • Raceme: an unbranched elongated main axis whose flowers have pedicels that are all about the same length
  • Spike: an unbranched, elongated main axis whose flowers have very short or no pedicels
  • Corymb: unbranched, elongated axis whose flowers have pedicels of unequal length, forming an inflorescence that appears flat-topped
  • Simple umbel: peduncle bearing all of the pedicels at its apex
  • Compound umbel: a cluster of simple umbels at the apex of a main axis
  • Head: a peduncle bearing flowers that have no pedicels
  • Catkin: spikelike inflorescence that bears only unisexual flowers
  • Spadix: type of spike inflorescence having small flowers borne on a fleshy stem
• Follicle stimulating hormone (FSH) promotes follicular growth and maturation.
• Flower divisible into mirror images on only one axis

  Bilateral / zygomorphic symmetry
• 4 main parts of flower
• what are the 4 main parts of flowers

  sepals, petals, stamens and pistils
• sepal - calyx
• petals - corolla
• stamen - androecium
• pistil - gyonecium
• How can the number of carpels compromising a gynoecium be determined ? 1. Count the stigmas or stigmatic lobes 2. Count the styles 3. Count the lobes of the ovary 4. Count the locules in the ovary 5. Count rows of placentae
• What is the term used to describe the arrangement of floral organs around the flower axis? Perianth
• The perianth consists of what two structures? Calyx (sepals) and Corolla (petals)