Classification

BENTHAM AND HOOKER’S SYSTEM OF ANGIOSPERM CLASSIFICATION INTRODUCTION • Classification denotes the arrangement of a single plant or group of plants an distinct category following a system of nomenclature, and in accordance with a particular and well established plan. • Some of the earlier systems of classification of angiosperms were artificial systems, since they used only certain superficial characteristics as the basis. • With more and more detailed study on the morphological, physiological and reproductive aspects of angiosperms, the artificial systems of classifications were replaced by the natural systems of classification. • George Bentham and Joseph Dalton Hooker - Two English taxonomists who were closely associated with the Royal Botanical Garden at Kew, England have given a detailed classification of plant kingdom, particularly the angiosperms. • They gave an outstanding system of classification of phanerogams in their Genera Plantarum which was published in three volumes between the years 1862 to 1883. It is a natural system of classification. • They described 97,205 species of flowering plants grouped into 202 orders (now recognised as families). • The system has the advantage of being the first great natural system of classification, which is very easy to follow. George Bentham 1800-1884 Joseph Dalton Hooker 1817-1911 SUB-CLASS - POLYPETALAE petals separate Series THALAMIFLORAE DISCIFLORAE CALYCIFLORAE Orders Orders Orders Ranales Geraniales Rosales Parietales Olacales Myrtales Polygalineae Celastrales Passiflorales Caryophyllineae Sapindales Ficoidales Guttiferales Umbellales Malvales THALAMIFLORAE Many stamens in the androecium. Flower is hypogynous Orders Ranales Parietales Polygalineae Caryophyllineae Guttiferales Malvales Families Families Families Families Families Families Ranunculaceae Sarraceniaceae Pittosporaceae Frankeniaceae Elatinaceae Malvaceae Hypericaceae Sterculiaceae Dilleniaceae Papaveraceae Tremandraceae Caryophyllaceae Portulacaceae Guttiferae Tiliaceae Calycanthaceae Cruciferae Polygalaceae Tamaricaceae Theaceae Magnoliaceae Capparaceae Dipterocarpaceae Annonaceae Resedaceae Sarcolaenaceae Menispermaceae Cistaceae Berberidaceae Violaceae Nymphaceae Canellaceae Bixaceae. DISCIFLORAE Hypogynous flowers with a cushion-like disc around or below the ovary Orders Geraniales Olacales Celastrales Sapindales Families Families Families Families Linaceae Olacaceae Celastraceae Sapindaceae Humiriaceae Aquifoliaceae Stackhousiaceae Meliosmaceae Malpighiaceae Rhamnaceae Anacardiaceae Vitaceae Coriariaceae Zygophyllaceae Moringaceae Geraniaceae Rutaceae Simaroubaceae Ochnaceae Burseraceae Meliaceae Dichapetalaceae CALYCIFLORAE Flowers epigynous or perigynous Thalamus is in the form of a cup Orders Rosales Myrtales Passiflorales Ficoidales Umbellales Families Families Families Families Families Connaraceae Rhizophoraceae Loasaceae Cactaceae Umbelliferae Araliaceae Leguminosae Combretaceae Turneraceae Aizoaceae Myrtaceae Cornaceae Rosaceae Passifloraceae Melastomataceae Saxifragaceae Cucurbitaceae Lythraceae Crassulaceae Begoniaceae Onagraceae Droseraceae Datiscaceae Hamamelidaceae Bruniaceae Haloragaceae SUB-CLASS - GAMOPETALAE petals fused Series INFERAE HETEROMERAE BICARPELLATAE Orders Orders Orders Rubiales Ericales Gentianales Asterales Primulales Polemoniales Campanulales Ebenales Personiales Lamiales INFERAE Flowers with inferior ovary Orders Rubiales Asterales Campanulales Families Families Families Caprifoliaceae Valerianaceae Stylidaceae Dipsacaceae Rubiaceae Goodeniaceae Calyceraceae Campanulaceae Compositae HETEROMERAE Flowers with superior ovary Number of carpels - more than two Orders Ericales Primulales Ebenales Families Families Families Ericaceae Plumbaginaceae Sapotaceae Clethraceae Primulaceae Ebenaceae Epacridaceae Myrsinaceae Styracaceae Diapensiaceae Lennoceae BICARPELLATAE Ovary superior, with 2 carpels Orders Gentianales Polemoniales Personiales Lamiales Families Families Families Families Oleaceae Polemoniaceae Scrophulariaceae Myoporaceae Salvadoraceae Hydrophyllaceae Globulariaceae Verbenaceae Apocynaceae Boraginaceae Lentibulariaceae Labiatae Asclepiadaceae Convolvulaceae Gesneriaceae Plantaginaceae Loganiaceae Solanaceae Bignoniaceae Gentianaceae Pedaliaceae Acanthaceae MONOCHLAMYDEAE only 1 kind of perianth Series Multiovulate Multiovulate Achlamydo Ordines Curvembryae Microembryae Daphnales Unisexuales Aquaticae Terrestris -sporae Anomali Families Families Families Families Families Families Families Families Nyctaginaceae Podostemaceae Nepenthaceae Piperaceae Lauraceae Loranthaceae Euphorbiaceae Salicaceae Amaranthaceae Cyinaceae Chloranthaceae Proteaceae Santalaceae Balanopaceae Empetraceae Myristicaceae Myristicaceae Thymelaeaceae Balanophoraceae Urticaceae Ceratophyllaceae Chenopodiaceae Monimiaceae Penaeaceae FicoidalesPlatanaceae LacisternaceaeFicoidales Batidaceae Elaegnaceae Leitneriaceae Polygonaceae Juglandaceae Phytolaccaceae Myricaceae Casuarinaceaeficoidales Betulaceae CLASS-MONOCOTYLEDONAE 1 cotyledon, flowers trimerous Series Microspermae Epigynae Coronarieae Calycinae Nudiflorae Apocarpae Glumaceae Families Families Families Families Families Families Families Hydrocharitaceae Scitamineae Roxburghiceae Flagellariaceae Pandanaceae Triuridaceae Eriocaulaceae Juncaceae Alismataceae Centrolepidaceae Burmanniaceae Bromeliaceae Liliaceae Cyclanthaceae Palmae Typhaceae Najadaceae Restionaceae Orchidaceae Haemodoraceae Pontederiaceae Philydraceae Araceae Cyperaceae Iridaceae Xyridaceae Lemnaceae Gramineae Amaryllidaceae Mayacaceae Taccaceae Commelinaceae Dioscoreaceae Rapateaceae DRAWBACKS • Gymnosperms were placed between Dicots and Monocots. • Many important floral characters were neglected. • It is not a phylogenetic scheme. • Some of the closely related families have been separated and placed under different cohotrs and a number of unrelated families put together. • Some advanced families like Orchidaceae have been regarded as primitive by placing in the beginning. .

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