Presentation on theme: "WHAT IS THE NATURAL SYSTEM?"— Presentation transcript:
1NATURAL SYSTEM OF PLANT CLASSIFICATION ACCORDING TO CHARLES BESSEY BY: ASHLEY BECK
2WHAT IS THE NATURAL SYSTEM? A phylogenetic system of organizing flowering plants with the use of genetic techniques.Besse’s theory was based off of evolution.
3THE NATURAL SYSTEM“Besse’s 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.
4THE NATURAL SYSTEMThe 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.
5THE NATURAL SYSTEMAn example of the primitive flower would be the Ranunculus, buttercup flowers.
6THE NATURAL SYSTEMA more advanced type of flowering plant would be the catkin inflorescences.
7Natural System of Plant Classification By: Thursday labCharles Bessey
8BesseyPublished Work: The Phylogenetic Taxonomy of Flowering Plants
9Charles BesseyHe developed a set of rules or “dicta” stating which characteristics were primitive an which were advanced in flowering plants.
10Natural SystemA 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.
11Those who started the Natural System were observing overall resemblances amongst plants, then making evolutionary connections.Similar to differences amongst the five kingdoms.