Dr. Ishwar Prakash Sharma discusses the historical development of plant classification systems. Early systems from 2000 BC divided plants based on single characteristics like appearance or habitat. The modern Linnaean system from the 1700s organized plants by their reproductive structures. Later natural systems grouped plants based on overall similarity. The current phylogenetic system, introduced in the 1800s, aims to classify plants based on evolutionary relationships and common ancestry as revealed by modern techniques. The modern combined system incorporates phylogenetic and natural approaches.

1. Dr. Ishwar Prakash Sharma
Herbal Research Department
Patanjali Research Institute, Haridwar, Uttarakhand
CLASSIFICATION SYSTEMS IN
PLANTS

2. Plant Systematics
Plant systematics is the branch of botany that is concerned with
the-
I- Identification
N- Naming
D- Description
C- Classification
 Classification of plants is a very ancient topics.
 First plant classification reported in Vedas around 2000 BC.
 Classification means the divination of something by the
basis of some properties.

3. Objectives of Taxonomy
o Determining what is a species (or their sub-divisions, as
subspecies)
o Distinguishing these species from others through keys and
descriptions and geographic boundaries and mapping their
distributions
o Investigating their interrelationships, and
o Determining proper names of species and higher order ranks
using international rules of nomenclature.
o In addition, some taxonomists investigate processes of
evolution that lead to the existing pattern of species and their
interrelationships.

4.  Around 400000 plant species are reported in the world now
(Stearn, 1980)
 The World Conservation Union’s (IUCN) Red List of Plants
included some 34,000 threatened species in 1997.
 60,000 to 100,000 plant species are currently threatened
 75% of the world’s population relies on traditional
medicines.
 Globally, 80% of our plant based calorie intake comes from
just 12 domesticated
 plant species (8 cereals,4 tubers) though 30,000 species of
plant are edible.
Why Classification?

5. Classification Systems

6.  Oldest and first approach of classification of plants
 Can not describe all plants
Classification of plants into different taxa based upon one or few
characteristics of plants which is selected by authors. Such as-
Reproductive behavior
Physical appearances
Habitat
Cotyledon etc.
Artificial classification

7. 1. Vedas ( ar. 200 BC.)
2. Theophrastus ( 370-285 BC.)
3. Secundus (23-79 AD.)
4. Dioscorides (62-128 AD.)
5. Magnus (1200-1280 AD.)
6. Brunfels ( 1464-1553 AD.)
7. Bock (1489-1554 AD.)
8. Fuchs ( 1501- 1556 AD.)
9. Tournefort (1656-1708 AD.)
10. Linnaeus (1707-1778 AD.)
Some important artificial system

8. Basis of some artificial classification system

9. 1. Monandria: (1 stamen)
2. Diandria: (2 stamens)
3. Triandria: (3 stamens)
4. Tetrandria: (4 stamens)
5. Pentandria: (5 stamens)
6. Hexandria: (6 stamens)
7. Heptandria: (7 stamens)
8. Octandria: (8 stamens)
9. Enneandria: (9 stamens)
10. Decandria: (10 stamens)
11. Dodecandria: (12 stamens)
12. Icosandria: (20 or more stamens)
13. Polyandria: (many stamens)
14. Didynamia: (4 stamens, 2 long and 2 short)
15. Tetradynamia: (6 stamens, 4 long and 2 short)
16. Monadelphia: (Stamens monadelphous)
17. Diadelphia: (Stamens diadelphous)
18. Polyadelphia: (Stamens polyadelphous)
19. Syngenesia: (Stamens synantherous)
20. Gynandria: (Stamens connate to gynoecium)
21. Monoecia: (monoecious plant)
22. Dioecia: (Dioecious plants)
23. Polygamia: (Polygamous plants)
24. Cryptogamia: Plant without flowers
Linnious system of classification

10. Advantages
Simple and easy
Need short time and information
Poorly known plant can be placed easily
Need very few instruments
Specifically focus on properties of interest
Disadvantages
Can not grouped all plant perfectly
Little predictive value
Arbitrarily selected properties do not necessarily correlate
well with each other
Cannot describe evolution
Advantages and disadvantages of Artificial
classification

11.  This taxonomic system was introduced by Jean Bauhin in
1623.
 These systems are based on natural affinities of plants.
 It is done based on natural characteristics of plant.
 It place together organisms that have the greatest number of
shared features.
 No single feature is not important but total features are the
tools of classification.
Natural Classification

12. 1. Gaspard Bauhin (1550-1624)
2. Ray ( 1627-1 705AD.)
3. Adanson (1727-1806)
4. A. L. de Jussieu ( 1748-1836)
5. Robert Brown ( 1773-1858)
6. A.P. Candole (1778-1884)
7. Alphonse (1806-1893)
8. Benthum ( 1800-1884) and Hooker (1817-1911)
Some Important Natural Classification System

13. Basis of some Natural classification system

14. Bentham & Hooker System of Classification

15. Advantages
More satisfactory on placing of species
More predictive value
Arbitrarily selected properties are necessarily correlate
well with each other
can be used to predict properties, not related the
classification
Contains more information about a species
Disadvantages
Complex than artificial
Need long time and more information
Poorly known plant can not be placed easily
Can not focus specifically on properties of interest
Advantages and disadvantages of Natural
classification

16.  Latest system of classification of life.
 Done in very micro scale (cells)
 Basic of the system is the Darwin's “Origin of Species (1859)”
 First introduced by August Wilhelm Eichler in 1883.
 Goal of the system is to establish a system of classification
based on the
 course of evolutionary descent of its members.
 System where it is believed that every species is come from
the evolutionary change.
Phylogenetic Classification

17. 1. Eichler (1839-1889)
2. Engler (1844-1930)
3. Prantl (1849-1893)
4. Bessey (1845-1915)
5. Sokal & Sneath (1963,73)
6. Hutchinson (1884-1972)
7. Takhtajan (1980)
8. Cronquist (1981)
9. Dahlgren (1981)
10. Thorne (1981)
11. APG (Angiosperm Phylogeny Group system)
Some Important Natural Classification System

18. Advantages
unique name for each species eliminates confusion
Maximum predictive value
Maximum detail scientific study
Contains maximum information about a species
Disadvantages
Most Complex than others
Need long time and research
Physical appearances are neglected
Physically same species can be in different groups
Advantages and Disadvantages of Phylogenetic
Classification

19. Arificial classification
Theophrastus ca. 300 B.C.
Linnaeus (1707-1778 AD.)
Natural classification
Benthum ( 1800-1884) and Hooker (1817-1911)
Phylogenetic classification
Hutchinson (1884-1972)
Takhtajan (1980)
APG (Angiosperm Phylogeny Group system)
Most Widely Accepted Systems

20. Now Phylogenetic and natural classification system is
combined to classification of plants
Modern Classification System

21. Historical Development of Plant Taxonomic System