Exam Capsule -Quick Revision Revision Notes- Plant Taxonomy

• Classification based on quantitative analysis of physical traits and evolutionary relationships is Cladistics
• Two taxonomic species are distinguished from each other by their failure to interbreed
• Spike with spathe known as Spadix is a typical inflorescence of the plant family Arecaceae
• families of plants have superior ovary: Brassicaceae ,Malvaceae , Polygalaceae

APG System of Plant Classification: (APG-Angiosperm Phylogeny Group)

• It is based on cladistic analysis of DNA sequences
• It is based on DNA sequences of two chloroplast genes and one gene coding for ribosomes
• Latest APG system is APG IV (2016)
• Cluster analysis is part of Numerical System  system of classification

Linnaean system of plant classification is called artificial, because he gave emphasis to Number of Stamens only in his classification of plants .

Andropogon aromaticus Sieber ex Schult. In the above given example of binomial nomenclature with author citation what the word ‘ex’ refers

It denotes the fact that an initial description did not satisfy the rules for valid publication, but that the same name was subsequently validly published by a second author or authors (or by the same author) in a subsequent publication

• Cladistics: A system of classification based on the phylogenetic relationships and evolutionary history of groups of organisms.
• Cladistic Taxonomy:  1.Ancestral history  2. Divergence from a common ancestor

• In taxonomy, according to the Law of Priority, The first properly published name of a species or genus takes precedence over any subsequently published one
• The international consortium for molecular taxonomy is COBOL
• Genes for cytochrome oxidase is used for DNA barcode analyses.
• In a cladogram, The leaves represent individual species, the nodes denote points of divergence, the branches denote lines of descendance and the length of the branches denote the evolutionary distances.
• An evidence for the ‘molecular clock’ phenomenon is the Evolution of the Cytochrome gene

• Chronospecies : A group of one or more species derived from a sequential development pattern which involves continual and uniform changes from an extinct ancestral form on an evolutionary scale.
• For preservation in the herbarium, the specimens are treated with Heating , Repellents ,  Fumigants
• The first herbarium in the world was founded in Padua, Italy
• In the system of classification by Bentham & Hooker dicotyledonous plants have been classified as Polypetalae, Gamopetalae, Monochlamydae.
• In the plant name Capparislasiantha R.Br..ex.DC. The author citation indicated that Robert Brown and de Candolle have equal status
• Cruciferae: Siliqua
• Phylogenetic Classification: Charles Bessey ,  Robert Thorne,  Engler&Prantl
• A taxon should have a single correct name if the same name to be used for different species or taxa is known as Homonym

Melbourne Code – 2011

• Latin diagnosis is not mandatory for names published on or after 01/01/ 2012.
• Publication of taxa in electronic media is effective on or after 01/01/ 2012.
• The Code is named as International Code of Nomenclature for algae, fungi and plants.

Shenzhen Code 

• The current version of ICN accepted by International Botanical Congress in 2017