Bessey’s System of Classification

Bessey included many fundamental dispositions of Bentham and Hooker and Engler and Prantl’s systems. Bessey
Charles Bessey revolutionized the classification of angiosperms by his ideas on primitive vs advanced characters
• Hypothesized the primitive vs advanced state of many characters of plants
• Bessey’s ‘dicta’ or rules were the basis of his phylogenetic classification scheme.
The following are the important features of Bessey’s classification:
  • Seed plants were polyphyletic in origin and consisted of three phyla, one of which alone he described, namely the Arthophyta (Angiosperms).
  • Angiosperms were divided into Oppositifoliae (Dicots and Alternifoliae(Monocots).
  • Paleobotanical, embryological and morphological studies were used in the division of the various taxa and their subdivision.
  • Ranalian stock was taken to be primitive.
  • Bessy accepted the strobilobed theory of origin of the angiosperm flower (According to this theory flower is a modified system of laterals or phyllomers).
Bessey divided the monocots into 8 orders , among which were distributed 45 families. The dicots were placed under 24 orders and 255 families.
Previous Post Next Post