Welcome Dr Vinod B Shimpale Department of Botany

Welcome Dr. Vinod B. Shimpale, Department of Botany, The New College, Kolhapur shimpale@yahoo. com

System of Classification ü Takhtajan system of classification What is classification ? Is a general process related to categorization. Need of classification ? To delimit the taxa or organism. Historical concepts of relationships: v. Natural classifications- Bentham and Hooker v. Artificial classifications- Linnaceous v. Phylogenetic classification- Takhtajan system v. Molecular and Phylogenetic Revolution: APG system

Takhtajan System of Classification 1. Introduction 2. Outline of the system 3. Merits and demerits

Takhtajan system of classification Introduction: 1. Armen Takthajan was a Professor in Leningaurd, Russia. 2. He presented a system of classification of angiosperms for the first time in 1942 and thereafter its revised versions in 1954, 1966, 1968 & 1980. 3. This system is the modification of Cronquist system of classification. 4. He has published this system under the name ‘die evolution der angiosperm’ that means Flowering plants: Origin and Dispersal. 5. It is one of the phylogenetic system of classification. 6. According to this system angiosperms are monophyletic in origin and evolved from some ancient group of gymnosperms. 7. As this system is phylogenetic in nature, the evolutionary trends are as follows: • Woody plants precede herbaceous plants. • Evergreen trees precede deciduous woody plants. • Simple leaves precede compound leaves. • Reticulate venation precede parallel venation. • Cymose inflorescence is primitive and racemose is derived one. • Bitegmic ovule is primitive and other types are derived from it. • Apocarpae precede syncarpae. • Monocot embryo is evolved from dicot embryo. • Endospermic seeds are primitive and non-endoseprmis is advanced. • Entomophily gave rise to anemophily.

Outline of the system Dilleniidae 14 Asteriidae 10 Rosiidae 19 Caryophy liidae 3 Ranunculiidae 3 Alisma tiidae 2 Ha Areciidae 5 Liliidae 14 ma m 14 liida e Magnoliidae Magnoliopsida Liliopsida Magnoliphyta v Magnoliophyta includes all angiosperms v Magnoliopsida includes all dicots. v Liliopsia includes all monocots. v According to Takthajan class Magnolipsida is more primitive & other angiosperms are evolved from it. v Among dicots Magnoliidae is more primitive and Asteriidae is highly evolved while among monocots Alismatiidae is more primitive and Areciidae is most advanced.

Merits and demerits Merits 1. Most of the recent taxonomist are of opinion that this system has given better idea of phylogeny. 2. Formation of superorders in classification. 3. According to this system bisexual and polypetalous flowers precedes unisexual and gamopetalous flowers. 4. Origin of monocot from dicto, 5. Placement of csub-class Asteriidae among the dicot and Areciidae among the Monocots as more advanced which is acceptable at present day knowledge. Demerits 1. According to this system woody plants are more primitive and herbaceous are derived from it but it is not acceptable by majority of taxonomist. 2. In this system monocots are placed after dicots, whereas the recent systems of classification place them between primitive angiosperms and eudictos.

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