The document discusses the Takhtajan system of classification for flowering plants developed by Armenian botanist Armen Leonovich Takhtajan. Some key points: - Takhtajan published his initial classification scheme in 1940 based on phylogenetic relationships, revising it several times until 1997. - His system recognizes a single division (Magnoliophyta) of two classes - Magnoliopsida (dicots) and Liliopsida (monocots). - It has advantages of being based on evolutionary relationships and forming small homogeneous families, but disadvantages include narrow criteria splitting related groups and placing monocots after dicots.

1. NAME: HASNAIN SARWAR
ROLL NO: 4128
DEPARTMENT: CHEMISTRY
TOPIC: TAKHTAJAN SYSTEM
OF CLASSIFICATION

2. TAKHTAJAN SYSTEM OF
CLASSIFICATION

3.  Armen Leonovich Takhtajan (1910-2009) was a Soviet-Armenian
botanist and one of the most important figures in 20th century for
plant evolution, systematics and biogeography. He is chiefly famous
as the author of works on the origins of flowering plants and
paleobotany. Takhtajan worked at the Komarov Botanical Institute in
Leningrad where he developed his 1940 classification scheme for
flowering plants, which emphasised phylogenetic relationships
between plants.
T

4.  The actual system of classification based on phylogenetic
principles was published in 1954. This system had later
gone through a series of modifications and elaborations (in
1966, 1980, 1987 and 1997) but the nucleus of the system
and the basic features of the branching pattern of phyletic
diagram remained essentially the same.
 Some of his important publications are :
a) Floristic regions of the world (1986)
b) Evolutionary trends in flowering plants (1991)
c) Diversity and classification of flowering plants (1997)
d) Flowering plants (2009)

5.  10. In the 1993 version of his , Takhtajan classification
recognised a single division Magnoliophyta consisting of 2
classes –
 Magnoliopsida (dicots) and Liliopsida (monocots).
 Class Magnoliopsida is classified into 11 subclasses, 55
superorders, 175 orders and 458 families.
 Class Liliopsida is classified into 6 subclasses, 16
superorders, 57 orders and 131 families.

7. Class : Magnoliopsida

 Subclass : Magnoliidae
 Nymphaeidae
 Nelumbonidae
 Ranunculidae

8.  Class : liliopsida
 Subclass : Liliidae
 Commelinidae
 Arecidae
 Alismatidae
 Triurididae
 Aridae


9.  The Takhtajan System of Classification
 13. The suffixes used for designation of texa in the classification are :
 a) Division – ‘phyta’
 b) Class – ‘opsida’
 c) Subclass – ‘idae’
 d) Superorder – ‘anae’
 e) Order – ‘ales’
 f) Family – ‘aceae’

13. ADVANTAGES
 It is based on phylogenetic relationship.
 This system is better organized on the basis of
evolutionary relation then older system.
 Families are small homogeneous unit. These are
composed of closely related genera.
 Sub class is not based on single character . It is
based on all known information.

14.  Angiosperms are treated as one division
Magnoliophyta.
 according to this system Angiosperms are
monophyletic. Monocot have originated from Dicot

15. DISADVANTAGES
 Narrow criteria are used for defining texa. It causes unwanted splitting of
related groups.
 According to this system monocot is derived from main ancestor to
Nymphaeales. It is the main drawback of this system.
 Monocot are placed after dicots. but recent system of classification place
them between primitive Angiosperm and Eudicots.

16. SUMMARY