HUTCHINSON SYSTEM OF CLASSIFICATION

            This system of classification was proposed by John Hutchinson (1884-1970) and is the best known and accepted phylogenetic system of classification. This system of classification has been published in his famous book ‘Families of Flowering Plants’ (1954-1960).

            According to Hutchinson, double perianth, bisexual conditions with woody arboreal habit are considered the most primitive. The primitive polypetalous forms have been diverged from the very beginning along with two separate lines. One of the lines still retains the arboreal habit, whereas the other line adopted the herbaceous habit.

            The first order of the arboreal line is the Magnoliales and the first order of the herbaceous line is the Ranales among dicotyledons. He placed monocotyledons after dicotyledons.

            Hutchinson divided the seed plants into two phyla –

            Phylum I: Gymnospermae :- (Seed remains naked)

            Phylum II: Angiospermae :- (Seed remains covered)

                        The phylum Angiospermae has been further divided into two sub-phyla –

                        Sub-Phylum I: Dicotyledons :- The sub-phylum Dicotyledons has been divided into two divisions –

                                    Division I: Lignosae (woody arboreal group) - Woody arboreal Lignosae consist of 54 orders, which begins with Magnoliales. This is followed by Annolales and end with Verbenales.

                                    Division II: Herbaceae (a herbaceous group) - The Herbaceae consist of 28 orders, which begins with Ranales and end with Lamiales.

                        Sub-Phylum II: Monocotyledons :- In Monocotyledons there are altogether 29 orders, which begins with Butomales and end with Graminales. The sub-phylum Monocotyledons has been divided into three divisions –

                                    Division I: Calyciferae (Distinct green calyx and coloured corolla)

                                    Division II: Corolliferae (More or less similar calyx and corolla)

                                    Division III: Glumiflorae (Much reduced perianth or without perianth or lodicules).

MERITS AND DEMERITS OF HUTCHINSON SYSTEM OF CLASSIFICATION

MERITS

(a) The families and orders in this system are of small size and comprise only very closely related taxa.

(b) This system is in conformity with the modern view of the phylogeny of angiosperms as it considers the Ranales and Magnoliales as the starting points among dicots.

(c) In this system, monocots are discussed after dicots.

DEMERITS

(a) Dicots have been divided into two major groups Lignosae and Herbaceae in this system. This kind of classification is outdated as the habit used to be the main basis of classification in the past era of Aristotle.

(b) Secondly, it also separates the families that have close affinities.

(c) This system is not much utility from the point of view of plant classification.

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