NATURAL SYSTEM OF PLANT CLASSIFICATION ACCORDING TO CHARLES BESSEY BY: ASHLEY BECK

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NATURAL SYSTEM OF PLANT CLASSIFICATIONACCORDING
TO CHARLES BESSEYBY ASHLEY BECK
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WHAT IS THE NATURAL SYSTEM?

• A phylogenetic system of organizing flowering
  plants with the use of genetic techniques.
• Besses theory was based off of evolution.

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THE NATURAL SYSTEM

• Besses cactus was based on his 28 rules, which
  show the evolutionary trends in angiosperm.
• The most direct path represents the actual
  evolutionary history of a given group.

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THE NATURAL SYSTEM

• The most primitive, original flower was believed
  to have had many separate petals, stamens, and
  carpels.
• As they evolved the parts of the flowers either
  fused together, reduced, or became absent.
• The simple structures are not primitive, but have
  become simple as a result of a reduction from
  more complex parts.

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THE NATURAL SYSTEM

• An example of the primitive flower would be the
  Ranunculus, buttercup flowers.

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THE NATURAL SYSTEM

• A more advanced type of flowering plant would be
  the catkin inflorescences.

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Natural System of Plant Classification
By Thursday lab

• Charles Bessey
• 1845-1915

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Bessey

• Published Work The Phylogenetic Taxonomy of
  Flowering Plants

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Charles Bessey

• He developed a set of rules or dicta stating
  which characteristics were primitive an which
  were advanced in flowering plants.

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Natural System

• A natural system is one which reflects the
  evolutionary relationships of the organisms. In
  this type of classification, all the members of a
  category (family, order, etc.) are known or
  presumed to be monophyletic, meaning they share a
  common ancestor.

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• Those who started the Natural System were
  observing overall resemblances amongst plants,
  then making evolutionary connections.
• Similar to differences amongst the five kingdoms.