Hutchinson Classification of plants

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Hutchinson Classification

History

John Hutchinson was a British Botanist gave a phylogenetic system of classification.

Hutchinson developed a system of classification for angiosperms which first appeared in his book entitled The Families of Flowering plants.

His classification was much closely related to Bentham & Hooker and Bessey classification rather than Englar and Prant system.

To some extent he revised the ‘Genera Plantarum’ of Bentham & Hooker under the title ‘The Genera of Flowering Plants ’under two volumes and not able to revise the whole.

Basis and Outline

Hutchinson recognized 111 orders and 411 families of flowering plants.

The Primitive ad Advanced forms were the basis of his classification.

According to him the primitive polypetalous forms diverged into two separate lines first line retain Arboreal habitat includes first order Magnoliales , the second line adopt Herbaceous habitat include first order Ranales .

The monocots and dicots were believed to be originated from a hypothetical Proangiosperm

The seed plants were divided into two phyla - Gymnosperms and Angiosperms, the later furthur divided into two sub phyla Monocotyledons and Dicotyledons.

Dicots has two furthur divisions Lignosaeae and Herbaceae .

Monocots include three groups:


He considers the primitive polypetalous forms diverged from the beginning along two lines, one

the tree like habit (Lignosae) and the Herbaceous habit (Herbaceae). In one type, Magnoliales, tree

like habit (arboreal type) is considered primitive and in the other the Ranales is considered (herbaceoushabit) as most primitive. Thus, Hutchinson divided Dicotyledons into two divisions 

1.The Lignosae and         2.The Herbaceae. 

According to him Monocots are divided into three divisions.

Lignosae include trees, shrubs and some herbsclearly derived from and related to other woody plants. Mainly it includes woody group.

Herbaceae includes herbs rarely shrubby lants related to and derive from herbaceous ones.

Gymnosperms are considered as more primitive than Angiosperms.

(I) Calyciferae- Flowers with a distinct calyx and corolla. This group begins with the family Butomaceae and ends with the family Marantaceae .

(ii) Corolliferae- Flowers with calyx and corolla more or less similar. This group begins with the family

Liliaceae and ends with the family Orchidaceae.

(III) Glumiflorae – Flowers with much reduced perianth or represented by lodicules. This group begins with the family Juncaceae and ends with the family Gramineae, which includes grasses which are wind pollinated, a condition that is correlated with extreme reduction in flower.


Merits

The system gave much better idea of phylogenetic concept.

Families and orders are small and comprise only closely related genera.

For widespread separation the families were increased to 411.

Placement of Magnoliales in Lignosae and Ranales in Herbaceae is agreed with prevalent view.

Abolishment of concept of Polypetalous, Gamopetaloua and Monochlamydous.

Arrange the taxa on the basis of set of characters not only one.

Provide useful keys for identification of taxa.

The phylogram for this system is superior to Besse’s system.

The derivation of monocot from dicots is agreed

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