Flower

• Flower - Main basis for plant identification and classification

  Structure: Modified twig adapted for reproduction

  Function: Forms the fruit and seeds
• Parts of a complete flower:

  Sepals - green, leaf-like structures which form the outermost floral whorl; collectively known as calyx.

  Petals - form a whorl next to the sepals; brightly colored; collectively known as corolla.

  Stamen (androecium) - male reproductive part

  • Anther
  • Filament

  Pistil (gynoecium) - female reproductive part

  • Stigma
  • Style
  • Ovary

  *Sepal and petals together form the perianth.
• Flower Parts

  A) Stamen

  B) Anther

  C) Filament

  D) Stigma

  E) Style

  F) Ovary

  G) Carpel

  H) Petal

  I) Ovule

  J) Sepal

  
• Variable features of flowers

  Color

  • Day-blooming flowers are generally brightly color
  • Night-blooming are usually white, creamy, or yellowish

  Odor

  • Some may be fragrant, pleasant, and sweet
  • Others are unpleasant or repulsive

  Parts Present

  • Complete - sepals, petals, stamen, and pistil are present
  • Incomplete - one part is lacking

  Sexuality

  • Perfect/Bisexual/Hermaphroditic - with both stamen and pistil
  • Imperfect/Unisexual - contains either the stamen or pistil

  *Staminate or Pistillate

  *Monoecious or Dioecious
• Nature of flowers

  Regular flowers - members of each set of organs are of the same shape and size

  Irregular flowers - some members of one or more sets of organs are different in size or shape or both.

  • Papilonaceous
  • Caesalpinaceous
  • Bilabilate/Two-lipped
  • Orchidaceous
• Other features

  Fusion of flower parts

  • Connation - when like parts are fused or united
  • Adnation - when dissimilar parts like sepals and petals are fused.

  Number of flower parts

  • Dicotyledonous - flower parts are in multiples of 4 to 5
  • Monocotyledonous - flower parts are in 3s

  Flower Symmetry

  • Radially Symmetry - actinomorphic flowers
  • Bilaterally Symmetrical - zygomorphic flowers

  Position of the ovary

  • Superior ovary - sepals and petals are attached below the ovary
  • Inferior ovary - sepal and petals are attached above the ovary
• Flower Symmetry

  A) actinomorphic

  B) zygomorphic

  
• Position of the ovary

  A) ovary superior

  B) ovary inferior

  C) hypanthium

  
• Placentation

  • Placenta - site where in ovules are attached in the ovary
  • Placentation - arrangement of placenta inside the ovary
• Types of Placentation

  • Marginal Placentation - placentae are located on the wall of a single ovary
  • Parietal Placentation - the placentae are found on the wall of a compound ovary
  • Axile Placentation - placentae are found at the central axis of a compound ovary.
  • Basal Placentation - placentae with a single ovule is found more or less at the base of the ovary.
• Placentation

  A) column

  B) axile

  C) parietal

  D) marginal

  E) basal

  
• Inflorescence - Arrangement of flowers on a stalk along the stem.

  General Types:

  • Determinate inflorescence - the oldest flower is at the terminal part of the main axis and the general progression of blooming is outward.
  • Indeterminate inflorescence - the younger flowers is terminal on the floral axis and the progression of blooming is inward.
• Inflorescence

  A) spike

  B) raceme

  C) corymb (simple)

  D) corymb (compound)

  E) panicle

  F) fascicle

  G) glomerule

  H) simple umbel (indeterminate)

  I) simple umbel (determinate)

  
• Inflorescence

  A) thyrse

  B) verticillaster

  C) compound raceme

  D) simple corymb of heads

  E) compound umbel (indeterminate)

  F) raceme of spikes

  G) panicle of spikelets

  
• Inflorescence

  A) catkin/ament

  B) spadix

  C) hypanthodium

  D) spikelet (grass)

  E) head/capitulum

  
• Placentation

  A) ovary wall

  B) locule

  C) ovule

  D) funiculus

  E) placenta