1. Aristotle (382 B.C.) :- Father of biology and father of zoology
- Time - 370 - 285 B.C.
- He is known as father of ancient plant taxonomy and father of botany.
- Both Theophrastus and Aristotle are Greek political philosophers.
- Theophrastus wrote many books on plants. Few of them are as follows
- Historia plantarum
- Causes of plants
- Enquiry into plants
- Theophrastus gave names and descriptions of 480 plants in his book Historia plantarum.
- Theophrastus proposes the first classification of plant kingdom. He classified plant kingdom in to four groups on the basis of growth habit-(a) Trees (b) Shrubs (c) Under shrubs (d) Herbs
- It is artificial classification.
- He proposed the term Annual, Biennial and Perennials.
3. Carolus Linnaeus :- [1707 - 1778]
- His real name was Carl Von Linne
- On the basis of work in latin language, he changed his name to Carolus Linnaeus. He was the Swedish scientist
- He is known as father of taxonomy, father of plant taxonomy and father of animal taxonomy.
- Linnaeus gave the two kingdom system classification. He grouped plants and animals into kingdom Plantae and kingdom Animalia respectively.
- Linnaeus wrote many books. Some important books are
- Hortus uplandicus - First book
- Flora lapponica
- Philosophia botanica
- Critica botanica
- Systema naturae (1737)
- Genera plantarum
- Species plantarum - last book (1753)
- In “Philosophia botanica”Linnaeus gave the principles of nomenclature.
- In “Systema naturae” Linnaeus gave the scientific names of animals. In this book he gives the detailed description of animal kingdom. He also gave the outline classification of plant kingdom in this book.
- In “Genera plantarum” Linnaeus gave the detailed description of plant kingdom.
- He classified the plant kingdom into 24 classes on the basis of stamens and style.
- This was an artificial classification.
- The main basis of Linnaeus classification was the “Sex organs”. Therefore this classification is also
known as “Sexual classification”.
In “Species plantarum” he gave the scientific names of plants. [He gave the description of 6000 plant species]
4. A.P. De Candolle
- He wrote the book “Theories Elementaire de la botanique”
- He was the first to propose the significance of vascular tissue in taxonomy.
- On this basis of vascular tissue he classified plants into two groups
- Cellular plants (Non vascular plants)- this group includes Thallophyta and Bryophyta
- Vascular plants- This group includes Pteridophyta, Gymnosperm and Angiosperms.
5. George Bentham (1800 - 1884) and Joseph Dalton Hooker (1817 - 1911)
- Both Bentham and Hooker were related to Royal botanical garden.
- Scientists working in botanical garden are known as curator.
- They wrote the book “Genera plantarum” (1862 - 1883). In this book, Bentham and Hooker gave the biggest and natural classification of spermatophyta i.e. plants with seeds.
In Genera plantarum, there is description of 202 families. In it,basically the description of seeded plants is present.
Merits of Bentham and Hooker classification
- The classification of Bentham and Hooker was natural formal.
- The classification of Behtham and Hooker was mainly based on the floral characters. This was very appreciable because floral characters are more stable than vegetative (root, stem, leaves) characters.
- It is the simplest classification. Therefore the arrangement of all plants in the botanical gardens and herbarium of the world is based on it.
- Although it is not the best classification but yet the arrangement of plants in botanical gardens and herbariums is based on it, because it is the simpler one. The main reason for its simplicity is that this classification is based on actual observations.
Demerits of Bentham and Hooker classification:-
- In this classification the phylogeny of plants is not considered, because in it, gymnosperms are placed in between dicots and monocots.
- The sequence of evolution is as follows :- Phylogeny = Gymnosperm Dicots Monocots
6. A.W. Eichler
- Syllabus de vorlesungen uber phanerogamen kunde - Book written by Eichler.
- In this book, Eichler gave the first phylogenetic classificationof plant kingdom.
- The classification of Eichler is very little phylogenetic.
- In this way Eichler classified plant kingdom into five divisionsand arranged them in the order of evolution (Phylogeny).
- Thallophyta Bryophyta Pteridophyta Gymnosperm Angiosperm
7. Engler (1844 - 1930) and Prantl (1849 - 1893)
- Book - “Die Naturlichen Pflanzen Familien”
- He gave the phylogenetic classification of plant kingdom. This classification was more phylogenetic as compared to Eichler’s classification.
8. Oswald Tippo
- Proposed the biggest phylogenetic classification of plant kingdom.
- This classification is the complete classification of plant kingdom.
- This is the most acceptable classification for books and study.
- Cyanophyta – B.G. Algae
- Euglenophyta – Euglenoids
- Chlorophyta – Green algae
- Chrysophyta – Yellow - Green - algae
- Pyrrophyta – Dinoflagellates and Diatoms
- Phaeophyta – Brown algae
- Rhodophyta – Red algae
- Schizomycophyta – Bacteria
- Myxomycophyta – Slime molds (false fungi)
- Eumycophyta – True fungi
These ten divisions include three types of organisms :- Algae (7 - division), Bacteria (1 - division) and Fungi (2 - division)
9. Karl Menz
- He showed the importance of serology in taxonomy.
- Similarities and dissimilarities in structure of proteins help to know the phylogenetic relationship of living beings. Living organisms which are phylogenetically close relatives have more similarities in their proteins. Organisms which are distantly related have different proteins.
Note: Phylogenetic relationship of plants and animals can be established by animal serum.Serology indicates that chimpanzee is closest relative of man.
- Haeckel gave the three kingdom (Protista, Plantae, Animalia) system of classification.
- Haeckel established the kingdom Protista.
- The term ‘Protista’ was given by C. Cuvier.
- Haeckel grouped those living organisms in Protista which did not have tissues.
- Kingdom Protista Prokaryotes, Protozoa, Porifera, Algae and fungi
- First tissue was originated in animal kingdom in Coelentrata
- First tissues was originated in plant kingdom in Bryophyta
He gave the Four kingdom system of classification.
- Mychota :- Dougherty and Allen gave the name “Monera” to Mychota of Copeland. All the prokaryotes are grouped in Monera
- Protista or Protctista:- Copeland grouped those eukaryotes in protista, which are visuallydifferent than normal plants and animals. Eg. Brown algae, Red algae, Fungi, Protozoa
- Plantae or Metaphyta:- Remaining all eukaryotic plants are grouped.
- Animalia or Metazoa:- Remaining all eukaryotic animals are grouped.
12. R. H. Whittaker (1969)
- He gave the Five kingdom system of classification.
- This classification was believed to be modern
- The five kingdom classification of Whittaker was based on 3 main characters
- Complexity of Cell :- Cell is prokaryote or Eukaryote , on this basis , kingdom Monera is formed. And all the prokaryotes are grouped in to it.
- Complexity of organism :- Organism is unicellular or multicellular , on this basis kingdom Protista was formed, and all the unicellular eukaryotes are grouped into it.
- Nutrition :- Organism is autotrophic or heterotrophic , on this basis kingdom Mycota, Plantae and Animalia were formed. Except fungi (heterotrophic) all the plants are autotrophs. Therefore fungi is separated from plants and placed in kingdom mycota. And remaining all the autotrophic plants are placed in kingdom - Plantae. Since all the animals are heterotrophs, therefore they are placed in fifth kingdom i.e. kingdom Animalia.
- Monera :-All the prokaryotes (Eubacteria, Rickettsia Actinomycetes, BGA, Archaebacteria,Mycoplasma)
- Protista :- All the Unicellular eukaryotes (Dinoflagellates, Diatoms, Euglenoids, Slime mouldsand Protozoans)
- Mycota :- True fungi
- Plantae :- All the multicellular plants – Algae, Bryophyta, Pteridophyta, Gymnosperm,Angiosperm
- Animalia :- All the multicellular animals
Note : Domain is a super kingdom category and extra taxonamic catagory