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Systematics: The Science Of Biological Diversity Chapter 12. Systematics - the scientific study of biological diversity and its evolutionary history. Theophrastus (370-285 B.C.). Father of Botany, student of Aristotle. Classified plants based on form. Tree Shrub Undershrub Herb.
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Systematics: The Science Of Biological DiversityChapter 12 • Systematics- the scientific study of biological diversity and its evolutionary history.
Theophrastus (370-285 B.C.) • Father of Botany, student of Aristotle. • Classified plants based on form. • Tree • Shrub • Undershrub • Herb
Carol von Linné (1707-1778) • Swedish naturalist. • Species Naturae & Plantarum. • Plant descriptions. • Plant binomials- a two-term system of nomenclature. • Genus and species (specific epithet). • Example- catnip. • Nepeta cataria L. • “Nepeta floribus interrupte spicatus pedunculatis”
Taxonomy • Taxonomy- (gr. taxis- arrangement, nomos- law) the science of the classification of organisms. • Identifying, naming, classifying organisms. • Domain • Kingdom • Phylum- phyta • Class- phyceae • Order- ales • Family- aceae • Genus • Species
Prokaryotes and Eukaryotes Prokaryotes Eukaryotes
International Code of Botanical Nomenclature (ICBN) • Aim- to provide a stable method of naming taxonomic groups. • Principle I- botanical nomenclature is independent of zoological and bacteriological nomenclature. • Principle II- names of taxonomic groups are determined by means of nomenclatural types. • Principle III- nomenclature of a taxonomic group is based upon priority of publication. • Naming- the purpose of giving a name to a taxonomic group is not to indicate its characters or history, but to supply a means of referring to it and to indicate its rank.
Taxonomic Terminology • Taxon- a taxonomic group of any rank (plural: taxa). • Synonym- two or more names that apply to the same taxon. • Basionym- the original name of a taxon. • Author/s- the first person or persons to describe a taxon. • Revisionary author/s- the person or persons that modified the name. • Etymology- the derivation, origin, or history of a word. • Type Specimen- a specimen designated to serve as a reference point for a scientific name. • Holotype • Lectotype
Taxonomic Names • Species names consists of the genus name, plus the specificepithet. • Members of a species may be grouped into subspecies or varieties.
How do you identify plants? • Ask an expert. • Use a herbarium. • Compare plant with a written description. • Use books to picture I.D. specimens. • Photographs and illustrations. • Use a dichotomous key.
Dichotomous Keys • A method employed for identifying unknown organisms. • A dichotomous key is constructed of a series of couplets, each consisting of two separate statements. 1. Flowers white .................. Plant A 1. Flowers red or yellow ..... 2 2. Petals red ............ Plant B 2. Petals white ........ Plant C