1. Introduction to Plant Taxonomy and Systematics
Field Botany
Introduction to Plant Taxonomy and Systematics

2. Reading assignments Judd et al.: Chapter 1, especially pages 1-5
( are merely examples – do not memorize!)

3. Definitions
Systematics is synonymous with taxonomy, though the latter has a more old-fashioned connotation.
The science of discovering, describing, and interpreting diversity among organisms.
NOT just “naming,” although nomenclature is one part of it.

4. Systematics includes:
Classification – Developing a logically organized scheme of categories and relationships, and placing organisms in it.
Nomenclature – Naming the categories in the classification system, using standardized rules for efficient communication.
Identification – Finding the name of an unknown organism, in relation to a pre-existing classification system.

5. Major groups of plants Green algae
Not technically placed in the plant kingdom, but recent evidence clearly shows they are the closest relatives to it.
Like the land plants, they have chlorophylls a & b and store energy as starch inside the chloroplast.
Simple reproductive structures, external fertilization.
We will not consider them further.
All other plants are called “embryophytes.”
Most live on land.
Embryo fertilized and retained on the mother plant.

6. Major groups of embryophytes
Non-vascular plants (bryophytes):
No water-conducting xylem and phloem.
Mosses, liverworts, hornworts
Vascular, non-seed plants
Ferns, clubmosses, spikemosses.
Vascular, seed, non-flowering plants (Gymnosperms)
Conifers, including pine
Vascular, seed, flowering plants (Angiosperms)
Most of the plants on earth!

7. Basics of nomenclature (more later!)
Binomial nomenclature: Every species has a two-word name
First word is genus (plural genera).
Second word is specific epithet.
The species is the 2-word combination.
Often accompanied by the “authority” – the name of the person who gave this name to the species.

8. Standard form for binomials
Genus name is always capitalized.
Specific epithet is never capitalized.
Specific epithet can never stand alone, though the genus name can be abbreviated to one letter.
Genus name and specific epithet are italicized or underlined (separately)
This applies to the genus name if used alone, too.
Authority is not underlined or italicized. Standard abbreviations exist for some authorities.

9. Examples Quercus alba L. Pinus ponderosa Dougl.
Quercus virginiana Mill.
Ledum groenlandicum (Oeder) Kron & Judd
How plants get their names will be discussed in later lectures.

10. The hierarchy of classification
Groups within groups.
Several* species together form a genus.
Several* genera together form a family.
Several* families together form an order.
Several* orders together form a class.
Several* classes together form a phylum.
Several* phyla together form a kingdom.
*but in some cases it might be only one.

11. Taxon
The word taxon just means any named group, at any level, whether a species, family, class, or whatever.
Plural is taxa.

12. Standard endings for taxa For a more complete list see p. 515.
Genus does not have a standard ending.
Family: -aceae
Order: -ales
Class: -opsida
Phylum: -phyta
Taxa above genus are capitalized, but not italicized or underlined

13. Exceptions to -aceae
There are 8 large families for which the rules allow two names: modern and traditional.
For the first 7 of these, you must know BOTH.
Common name
Traditional name
Modern name
Sunflower
Compositae
Asteraceae
Mustard
Cruciferae
Brassicaceae
Grass
Gramineae
Poaceae
Mint
Labiatae
Lamiaceae
Pea
Leguminosae
Fabaceae
Carrot
Umbelliferae
Apiaceae
Palm
Palmae
Arecaceae
Clusia
Guttiferae
Clusiaceae