The Science of Plant Classification

GOALS of TAXONOMY IDENTIFY all members of the plant kingdom NAME all plants ARRANGE plants into a HIERARCHY that indicates their TRUE relationship to another

HISTORY of PLANT CLASSIFICATION ARTIFICIAL CLASSIFICATION NATURAL CLASSIFICATION PHYLOGENTIC CLASSIFICATION

ARTIFICIAL CLASSIFICATION Form and Use Ancient Greeks THEOPHRASTUS ( BCE) DIOSCORIDES (40-90 CE)

ARTIFICIAL CLASSIFICATION Middle Ages Monocots vs. dicots Vascular vs. non-vascular Descriptive names Herbalists herbariums

ARTIFICIAL CLASSIFICATION LINNAEUS ( CE) Binomial Nomenclature System based on the flower and sexual parts

NATURAL CLASSIFICATION System based on MORPHOLOGY of plant parts (shape or form) French Botanists Used today, although not considered “true relationships”, but closer

PHYLOGENETIC CLASSIFICATION Based on TRUE GENETIC relationships of plants CHARLES DARWIN ( CE) Origin of Species (1859) Theory of Evolution explained Natural Selection as a means of adaptation

TAXONOMY TODAY Made up of NATURAL and PHYLOGENETIC classification Governed by International Code of Botanical Nomenclature (ICBN) Rules for naming plants Revised as new evidence becomes available Dynamic – ever changing system Based on observations and systematic gathering of evidence