includes seed plants. II Arthur Cronquist system of classification Arthur Cronquist ( - ) an eminent American taxonomist proposed phylogenetic classification of flowering plants Figure . : Arthur Cronquist based on a wide range of taxonomic characters including anatomical and phytochemical characters of phylogenetic importance. He has presented his classification in in his book titled “ The evolution and classification of flowering plants .” His classification is broadly based on the Principles of phylogeny that finds acceptance with major contemporary authors.
Cronquist classified the angiosperms into two main classes Magnoliopsida (=dicotyledons) and Liliopsida (= monocotyledons). There are subclasses, orders, families and about , species in Magnoliopsida, whereas in Liliopsida there are sub classes, orders, families and about , species. Cronquist system of classification also could not persist for a long time because, the system is not very useful for identification and cannot be adopted in herbaria due to its high phylogenetic nature. .
. Angiosperm phylogeny group (APG) classification The most recent classification of flowering plants based on phylogenetic data was set in the last decade of twentieth century. Four versions of Angiosperm Phylogenetic Group classification (APG I, APG II, APG III & APG IV) have been published in , , and respectively. Each version supplants the previous version.
Recognition of monophyletic group based on the information received from various disciplines such as gross morphology, anatomy, embryology, palynology, karyology, phytochemistry and more strongly on molecular data with respect to DNA sequences of two chloroplast Division: Embryophyta (Siphonogama) Sub-division: Gymnospermae Sub-division: Angiospermae Class: Monocotyledonae (includes orders families) Class: Dicotyledonae (includes orders) Archichlamydeae (Apetalae) (i) Corolla polypetalous (ii) Perianth single or double (iii) Includes orders families Metachlamydeae (Sympetalae) (i) Corolla Gamopetalous (ii) Perianth in two whorls (iii) Includes orders families Figure . : Outline of Engler and Prantl classification genes ( atp B and rbc L) and one nuclear gene (nuclear ribosomal 18s DNA). The most recent updated version, APG IV ( ) recognised orders and families. Of these, families