2. Taxonomy = the study of naming, describing and classifying organisms, including the rules, theories, principles and procedures Taxon = a group of organisms recognized at any level of a taxonomical hierarchy (e. g. Family, Class)
3. Classification = the orderly arrangement of organisms into a hierarchal system that is derived from an accumulation of information about the individual organisms, the end result expressing an interrelationship Why? Because it provides humans with a means to address organisms and their relationships to one another Because it allows humans to make inferences about unfamiliar organisms Because it is in our nature
4. Classification Systems: Artificial = based on obvious or convenient items of information called characters (e.g. flower color, locality). Natural = based on morphological features that give the sense of correlation with those of another organism. (e.g. trees, grasses) Phylogenetic = based on the proposed lineage derived from a wide variety of information.
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7. Carl von Linné Swedish botanist, zoologist, and physician First to illustrate the usefulness of binomial nomenclature Developed the modern taxonomic hierarchy
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11. Phylogenetic Classification = the evolutionary history of a species or group of species Typically represented as a phylogenetic tree (cladogram) a branching diagram showing the evolutionary relationships among various biological species or other taxa that are believed to have a common ancestor
18. Plant Classification Current classification systems follow the recognized taxonomic hierarchy, however, there is always some disagreement as to the membership requirements of various taxa The Core
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23. Identification = the assigning of an existing name to an unknown organism Methods Expert assistance – local university, school, museum Comparison method – guide books, internet Dichotomous key – local manuals, floras
24. Dichotomous Key Keys based on a sequence of pairs of contrasting statements The user chooses the statement that better describes the plant in question Each time a choice is made a number of plants are eliminated Eventually the number of possible identifications is reduced to one
25. Dichotomous Key 1. Growth habit an herb 1. Growth habit a vine, shrub or tree . . . . . . . . . . . . 2 . . . . 4 4. Growth habit a vine 4. Growth habit a shrub or tree . . . . . . . . . . . . 5 . . . . . . . 7 7. Growth habit a shrub 7. Growth habit a tree . . . . . . . . . . . . 8 . . . . . . . . . . . . 30