Course - BSc Botany Semester - IV Paper name Plant Systematics/ - PowerPoint PPT Presentation

• Course - BSc Botany • Semester - IV • Paper name – Plant Systematics/ BOT CC 410 • Topic – Hutchinson system of classification • Faculty Name – Dr Piyush kumar Rai • e.Mail I’d raipiyush518@gmail.com

JOHN HUTCHINSON (1884-1972) A British Botanist Who was Associated with the Royal Botanic Garden at Kew, England

• He proposed a system of Classification which was based on Bentham and Hooker and Bessey. • It is the best known and accepted Phylogeqnetic system of classification. • He orginally presented the system in his two volume work :The families of flowering plants.

• Vol – 1 : Dealing with the Dicotyledons in 1926 • Vol- 2 : Dealing with the Monocotyledons in 1934 • It was revised in 1948 in his British Flowering Plants and again in his second edition of The Families of Flowering plants.

PRINCIPLE ADOPTED BY HUTCHINSON (1959) • Evolution is both upward and downward . • Evolution does not necessarily involve all organs of the plant at the same time . • Evolution has generally been consistent • Trees and shrubs are probably more primitive than herbs .

• Perennials are older than biennials . • Aquatic flowering plants are as rule more recent than terrestrial and the same may be said of epiphytes, saprophytes and parasities . • Collateral vascular bundles arranged in a cylinder is primitive.

• Sìmple leaves precede compound leaves. • Bisexual precede unisexual flower and the dioecious is probably more recent than the monoecious condition. • Solitary flower is primitive. • Apocarpy is primitive and syncarpy is advanced

OUTLINE OF HUTCHINSON CLASSIFICATION

• Phylum : Angiospermae • Sub phylum l : Dicotyledons • Division I : Lignosae (54 order) : Order 1 Magnoliales- Order 54 Verbenales. • Division ll : Herbaceae(28 orders) : Order 55 Ranales- order 82 Lamiales.

• Subphylum Il : Monocotyledons • Division l: Calyciferae (12 order) : Order 83 Butomales to order 94 Zingiberales. • Division ll:Corolliferae (14 order) : order 95 Liliales to order 108 Orchidales • Division lll: Glumiflorae (3 order) : order 109: Juncales to order 111 Graminales.

MERIT OF HUTCHINSON SYSTEM OF CLASSIFICATION • The families and order in this system are of small size and comprise only very closely related taxa . • This system is in conformity with the modern view of the Phylogeny of Angiosperm as it considers the Ranales and Magnoliales as the starting points among dicot. • Monocots are discussed after dicots in this system.

• Reshuffling of genera and families. • Placing of gymnosperm before angiosperms in flowering plants .

DEMERITS OF HUTCHINSON SYSTEM OF CLASSIFICATON • 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. • Secondly it also separates the families that have close affinities. • This system has not much utility from the point of view of plant classification.

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