Plant Taxonomy

Accurate plant identification is more than just a means of avoiding poisonous plants. It is a skill which should be an essential requirement for anyone working with plants and especially in horticulture. Taxonomy is the term used to describe the practice and science of naming and classifying any organisms, and in our case plants. It relies on accurate descriptions and rules of nomenclature to facilitate identification. To attempt to select, grow, and use plants in any context without taxonomic skill is at best foolhardy, and at worst it can be outright dangerous.

There are also economic reasons for being able to identify plants. The development of new plant cultivars can be time-consuming and costly, but it is very important to commercial horticulture in order to improve continually the cultivars available in terms of productivity and quality. Anyone who devotes significant resources to developing a new cultivar needs to be able to establish and prove their commercial rights to that plant in order to obtain fair and profitable gain from their investment. Systems for establishing such rights exist in most developed countries.

Lesson Structure

There are 10 lessons in this course:

1. Introduction to Taxonomy
   • Introduction to Plant Taxonomy
   • Scientific Vs. Vernacular Names
   • Linnaeus
   • Binomials
   • Uniformity
   • Protein Analysis
   • Ranks and Language
   • Ranks of Classification - KPCOFGS
   • Plant Phyla
   • Plant Families
   • Genus and Species
   • Latin Names
   • Gardener's Ranks
   • Hybrids
   • Subspecies
   • Varieties
   • Cultivars
   • International Code of Botanical Nomenclature
   • The Basic Ideas
   • Principle of Priority
   • Legitimate Naming
   • Recent Changes to the Code
   • International Code of Nomenclature for Cultivated Plants
   • Taxonomic Name Resolution Service
   • International Plant Names Index
   • Trademarks & Patents
   • Plant Breeders Rights
   • The Rise of Molecular Data
   • The Impact of Molecular Data
2. Describing Plant Parts
   • Habit
   • Stems
   • Hairs
   • Leaves
   • Compound and Simple Leaves
   • Leaf Shapes
   • Leaf Margins
   • Leaf Structure
   • Leaf Arrangements
   • Leaf Venation
   • Leaf Modifications
   • Roots
   • Root Modifications
   • Terminology
   • Flowers
   • The Inflorescence
   • Fruits
   • Dry Fruits
   • Fleshy Fruits
   • Compound Fruits
   • A Key to the Main Types of Fruits
   • Terminology
3. Recording & Analysing Plant Descriptions
   • Herbaria - Collecting and Preserving a Plant
   • Fresh Material
   • Arranging Plants for Pressing
   • Pressing Difficult Specimens
   • The Drying Process
   • Herbarium Specimens
   • Photographs
   • The Problem of Colour
   • The Law Relating to Plant Collecting
   • Describing a Plant on Paper
   • The Equipment You Need
   • Botanical illustration
   • Floral Diagrams
   • Floral Diagram Technique
   • Floral Formulae
   • DNA Barcoding
   • Process of Using DNA Barcoding for Plant Identification
   • Applications of DNA Barcoding
   • CHEMICAL ANALYSIS (Chemotaxonomy)
4. Taxonomic Techniques
   • The advantages of using keys and their limitations
   • Using a key
   • The rules when making a key
   • Lamiaceae (Simplified Key)
   • Rules When Writing Couplets
   • Best Practice Points
   • Making a key
   • Why botanical families are so useful when identifying plants
5. Primitive Plants
   • The Bryophytes
   • Mosses
   • Liverworts
   • Hornworts
   • VASCULAR PLANTS or tracheophytes
   • Vascular Tissue and Why it is Important in Evolution of Life on Earth
   • A glossary to help you
   • The Lycopodiopsida (or Lycophytes)
   • Clubmosses - Plants in the family Lycopodiaceae
   • Quillworts - Plants in the Family Isoetaceae
   • Spike Mosses or Lesser Clubmosses – Plants in the Family Selaginellaceae
   • the euphyllophytes – the seed plants, horsetails, and ferns
   • The Seed Plants
   • Horsetails
   • The Ferns
6. Seed Plants
   • The gymnosperms
   • The cycads – 1 order, 3 families, 10 genera, 285 species
   • Ginkgo - 1 order, 1 families, 1 genus, 1 species
   • The Gnetidae - 3 orders, 3 families, 3 genera, 71 species
   • Welwitschiaceae - 1 Genus, 1 Species
   • Gnetaceae - 1 Genus, 30 Species
   • The conifers - 3 orders, 6 families, 69 genera, 591 species
   • The Conifers’ Life History
   • The Cycads, Ginkgo, and Gnetidae — How they Differ from the Conifers
   • The Six Families of Conifers
   • The Angiosperms
   • Flowers and Why they are Important in Evolution of Life on Earth
   • The Flowering Plant’s Life History
   • The Diversity of Angiosperms
7. Phylogeny of Land Plants
   • Introduction
   • Darwin’s Tree of Life Metaphor - The Hidden Bond of Descent
   • Why Use DNA Sequences for Classification?
   • The Principle of Monophyly
   • The Phylogeny of Land Plants
   • The major changes in flowering plant taxonomy
   • The End of the Monocot-Dicot Split
   • Finally, Some Resolution Within the Monocots
   • Some Surprises
   • Name Changes Resulting from the Increase in Evidence
   • When Applying the Principle of Monophyly Results in Name Changes
   • What we can learn from phylogenies
8. Monocotyledons
   • Summary of Important Families
   • The Monocots — SIGNIFICANT FAMILIES
   • Arecaceae
   • Aizoaceae (syn. Ficoidaceae)
   • Dioscoraceae
   • Liliaceae
   • Orchidaceae
   • Iridaceae
   • Amaryllidaceae
   • Asparagaceae
   • Arecaceae
   • Pontederiaceae
   • Musaceae
   • Bromeliaceae
   • Poaceae
   • Cyperaceae
   • Juncaceae
9. Dicotyledons (Part I)
   • IMPORTANT DICOT FAMILIES
   • Key to Selected Angiosperm Families
   • Lower-growing Soft-wooded Plants
   • Apiaceae
   • Asteraceae
   • Brasicaceae
   • Cactaceae
   • Crassulaceae
   • Euphorbiaceae
   • Gesneriaceae
   • Lamiaceae
   • Ranunculaceae
   • Solanaceae
10. Dicotyledons (Part 2)
    • Fabaceae - Papilionoideae, Mimosoideae, Caesalpinoideae
    • Fagaceae
    • Ericaceae
    • Magnoliaceae
    • Malvaceae
    • Myrtaceae
    • Ongaraceae
    • Rosaceae
    • Proteaceae
    • Rutaceae
    • Rubiaceae

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.