Plant Taxonomy

Course CodeBHT344
Fee CodeS3
Duration (approx)100 hours
QualificationStatement of Attainment

Learn to Classify Plants & Understand Differences Between Plant Groups  

Study this course to learn how to systematically examine a plant’s distinguishing characteristics, then determine its scientific classification based upon those observations.

This course provides a solid footing in plant taxonomy. It begins by introducing the binomial system and ranks of classification and then goers on to explore botany including all the different parts of plants in detail – roots, shoots, leaves, flowers, and fruits.

Students also learn about collecting, pressing, dissecting, drawing and analysing plant material. We then go into detail about the use and design of plant keys for identification purposes before a comprehensive exploration of all the major plant groups.

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
    • Arecaceae
    • Aizoaceae (syn. Ficoidaceae)
    • Dioscoraceae
    • Liliaceae
    • Orchidaceae
    • Iridaceae
    • Amaryllidaceae
    • Asparagaceae
    • Arecaceae
    • Pontederiaceae
    • Musaceae
    • Bromeliaceae
    • Poaceae
    • Cyperaceae
    • Juncaceae
  9. Dicotyledons (Part I)
    • 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

Scientific Plant Classification

The scientific system uses levels to classify plants by dividing them into groups which have similar physical characteristics. These groups are then divided into smaller groups with more similar characteristics. These are divided again, and so on. Therefore, the division of group to subgroup, and subgroup into further subgroups continues until you finally have only one type of plant in each group.

In the scientific system of plant classification there are over half a million species of plants.  The classification of plants, like the classification of anything else, is based on the idea of grouping together things which are similar. Species are groups of individual plants that have a range of similar characteristics and are capable of freely interbreeding with each other. That is, the pollen from the flower of one plant can successfully pollinate the flowers of another and the sperm in that pollen can fertilise the egg cells in the ovules of the second plant.  This results in a fertile seed which will germinate and produce a new fertile plant that resembles its parents. It should be noted that just because two plants can be hybridised in our gardens this does not automatically make them members of the same species. 

Species are grouped together into collections of species which are fairly similar. These groups are called genera, with the singular being genus. Genera are grouped into collections of genera which have a relatively great similarity to each other. These are called families. Families are the level which most horticulturists start at, and then work down to genus and species. In fact, it could be argued that the only way to gain a reasonable grasp of plant identification and culture is to learn plants by their family as well as their genus and species names. Familiarisation with plant families enables a person with no prior knowledge of a particular plant to be able to place it in a family and make an educated guess as to its growing requirements, susceptibilities to environmental factors, possible form and shape, and a range of other likely characteristics.

Why Plant Taxonomy is Important

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 to continually improve 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 to obtain fair and profitable gain from their investment. Systems for establishing such rights exist in most developed countries.

Who Will Benefit from Studying this Course?

This course is essential studying for anyone who works in the horticulture industry. Whether you have previously studied some taxonomy previously, or whether you are new to this subject, you will find this course fulfilling. 

The course is aimed primarily at those working in the fields of – botany, plant taxonomy, horticulture research, botanical gardens, general horticulture, cut flower industry, gardening, garden design, landscaping, and garden tourism. It is also suitable for anyone who wishes to brush up on their taxonomy skills or with a general interest in being able to name plants and understand plant morphology.    


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