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Merit d merit..hchinson ..takhtajan ..bassaey

This document summarizes and compares the classification systems of Takhtajan, Bassaey, and Hutchinson. It outlines the key merits and demerits of each system. Takhtajan's system from 1966 and revised in 1987 places dicots before monocots and uses small, homogeneous family units. However, it is criticized for extremely narrow taxa definitions. Bassaey's system from the 1800s was the first American phylogenetic system, but its placement of monocots before dicots is not justified. Hutchinson's system from the 1950s considers cytological and paleobotanical evidence but is based only on habit. It is criticized for its hypotheses about primitive angiosperms.

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Relative merits and demerits of major systems of classification: Takhtajan , Bassaey , Hutchinson Presented by : Panchal Rita C. M.sc sem : 2 Department of Life sciences, H.N.G.U., Patan
Content Takhtajan Systems Of Classification. Bassaey Systems Of Classification. Hutchinson Systems Of Classification.
Takhtajan Systems Of Classification Takhtajan ( 1910 to 2009 ) proposed evolutionary system of classification in " system and phylogeny of Flowering Plants (1966)" and revised in 1987. The latest revised edition of his classification published in " Diversity and Classification of Flowering Plants ( 1997)". His latest classification is according to ICBN.
Merits Dicots discussed prior to monocots. Dicots begin with most primitive living angiosperm Magnoliales. The families are small and homogeneous units made up of closely related genera. Cyperaceae and Gramineae are placed under separate orders.
Demerits The main demerits is extremely narrowly defined taxa , that has resulted in the un warranted splitting of the related groups. For example Papaveraceae kept away from order Capparales. Malvales have 10 orders , but based on palynology , embryology these can be divided into two orders Malvales and Tiliales.
Bassaey Systems Of Classification Bassaey ( 1845 - 1915 ) a student of Asa Gray was the first American Taxonomist to introduce phylognetic system of classification.
Merits The Gymnosperm which stand between the dicots and Monocots in Bentham and Hooker's system have not been considered. Order Asismatales among monocots and Ranales among dicots are placed at the base , because these two orders have been regarded as most primitive. Similarly Orchidaceae and Composite have been placed at the top , because of their being most advanced among monocots and dicots respectively.
Demerits Placing of monocots before dicots is not justified. Inclusion of families are Typhaceae , Sparganiaceae, Pandanaceae in Alismatales is not sound , as these families are supposed to be derived from Liliaceous ancestors. Similarly Najadaceae is placed under Tiliales.The family is more allied to Helobiales rather than Liliales.
Hutchinson Systems Of Classification He proposed a phylogenetic system of classification in his " The Families of Flowering Plants.” He published his revised classification in " British Flowering Plants."
Merits It is most phylogenetic system of classification based on natural characteristic of Plants. Cytological, anatomical, paleobotanical , studies have been considered for treatment of families. Placing of gymnosperm before angiosperm in Flowering plants. Many Families have been raised to the rank of orders legumiosae family raised to order Leguminales.
Demerits It is based on habit only and Lamiaceae and Verbenaceae are placed away from each other. There is no hypothesis for pro angiosperms. Magnoliaceae mentioned as most primitive family and according to other authors Winteraceae is the most primitive family which vessel less. In herbaceae , Lamiaceae is regarded advanced over Asteraceae . Infact Asteraceae have been treated as most advanced family of dicotyledons.
Reference Text book of Botany Angiosperms by: B.P.Pandey https:// en.m.wikipedia.org https://www.slideshare.net
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