Bessey included many fundamental dispositions of Bentham and Hooker and Engler and Prantl’s systems. 
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:
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).