THE PLANTS
Supergroup Plantae
• Original
photosynthetic
symbionts
• Includes the red
algae and the
green plants
• All with
somewhat
simple walls
Eukaryotic Domains
Green Plants
• Chlorophylls a and b
• Walls of cellulose
• Store starch
Generalized plant life history
Earliest Systems for Plants
• Mostly defined
functionally by
foragers, farmers,
and physicians
• Still used in terms
like weed, fruit (nontechnical usage),
herb, and vegetable
Illustration of an early herbal, De
Materia Medica (~50-70 C.E.) by
Dioscoides
Theophrastos of Lesbos
• Successor to Aristotle and
developed his philosophy in
many areas.
• Developed system of plants
in parallel with Aristotle’s
system on animals
• Structure of plants
– Herbs
– Shrubs
– Trees
c. 371-287 B.C.E., Athens
Karl von Linné
Carolus Linnaeus (1707-1778)
• Linne is reference to a large
lime tree near his ancestral
home
• Latinized his name to
Carolus Linnaeus
• Created a system on plants
using the sex organs as a
means of classification
• Species Plantarum (1753) is
the starting point for all
plant taxonomy
Key to the sexual system from the 10th
edition (1758) of Systema Naturae
Modern Systems based on
Morphology
• Unified botanical
information for North
America
Gray and Gleason
• Asa Gray (1810-1888)
• Henry Gleason (1882-1975)
• Univ of Michigan and Harvard • Univ Michigan, Univ Illinois, and
• Met Darwin at Kew through
New York Botanical Garden
Hooker
• Manual of Botany a standard • Revised Gray’s Manual
for 100 years
Molecular Phylogenetics of Plants
• PhyloCode (introduced in • Walter Judd (1951- )
1983)
• Univ of Florida
• American Phylogeny Group
• Plant Systematics, a
(also called Angiosperm
Phylogeny Group, first
Phylogenetic Approach
released 1991).
Green Plants
MAJOR CLADES OF THE
GREEN PLANTS. This system
reflects all of these changes
in the taxonomy of the
Viridiplantae with two
subkingdoms: Chlorobionta
and Streptobionta. See the
Tree of Life Project and
Palmer et al. (2004) for the
consensus view of the
molecular/ ultrastructural
relationships between the
higher taxa of the green
plants.
CH = Chlorobiont Clade
ST = Streptobiont Clade
EM = Embryophytes
VP = Vascular Plants
SP = Seed Plants
Green algal diversity
Bryophytes
Tracheophytes
• Plants have vascular tissue
– Xylem
– Phloem
• Usually with stems, roots, and leaves
Ferns
The Seed
Conifers and other Gymnosperms
Flowering Plants
• Contain flowers
• Fruit is derived from the ovulary of the flower
MAJOR CLADES OF THE
FLOWERING PLANTS
1. The Flowering Plants
2. The Basal Families
3. Plicate Flowering Plants
4. Magnoliids + Monocots
5. Magnoliids
6. Monocots
7. Dicots
8. Basal Dicots
9. Eudicots
Flower
Placement of ovulary
Major Types of Flowering Plants
•
•
•
•
Primitive Dicots
Magnolias and their relatives
Monocots
Derived Dicots
Primitive Dicots
Water Lilies
Amborella, sister to all other
living flowering plants
Magnolias and their Relatives
Magnolia flower
Avacado
Monocots
Orchid
Wheat
TABLE 1. Important grass grain plants of the world, their generic names, and the
regions of the Earth where the plants were domesticated. Much of this
information came from Glemin and Bataillon (2009).
GRAIN
GENERIC NAME
REGION OF
DOMESTICATION
Rice (Figure 25)
Oryza
Asia
Wheat (Figure 26)
Triticum
Middle East
Maize (corn; Figure 27)
Zea
Central America
Barley
Hordeum
Middle East
Pearl Millet
Pennisetum
South Africa
Foxtail Millet
Setaria
East Asia
Proso Millet
Panicum
Asia
Finger Millet
Eleusine
Ethiopia
Rye
Secale
Turkey
Oats
Avena
Middle East
Sorghum (milo)
Sorghum
Northern Africa
Derived Dicots
Flowers –large and small
Wolffia in flower, floating plant
Rafflesia, largest flower,
related to euphorbias and
parasitic on vines of SE Asia
Amorphophallus titanum,
largest unbranched
inflorescence, an aroid.
Arrangements of flowers
Largest Inflorescence
Types of fruits
Major Events in Plant Evolution
• Appearance of land
plants initially limited to
mosses and relatives
during Ordovician
Period (~470-440 mya)
based on fossil spores.
• Plants restricted to
lowlands and wet areas
of temperate to tropical
latitudes.
Mosses growing in a Scotland bog, their
success related to symbioses with fungi.
Likely, this was true at the time of the
earliest emergence. (David Beerling,
University of Sheffield)
Life on Land
Advantages
• Unfiltered light
• Atmosphere larger
reservoir of CO2
• Initially, fewer predators?
Disadvantages
• Exposure to UV light
• Need for water storage and
uptake
• Need for photosynthate
used for support
Major Events in Plant Evolution
• Vascular tissue
• Shift to dominance of
spore-producing
portion of life cycle
Restoration of Cooksonia from Silurian
Vascular
tissue in
stem of
Rhynia,
lower
Devonian
Telome Theory
Walter Max Zimmermann;
1892-1980, Germany
Major Events in Plant Evolution
Late Devonian
Pennsylvanian
Major Events in Plant Evolution
The Seed
Major Events in
Plant Evolution
Major Events in Plant Evolution
Major Events in Plant Evolution
These are from the lower Cretaceous, but
flowering plant pollen has been found in strata
100 my earlier.
Major Events in Plant Evolution
Wasp attempting to copulate
with an orchid
The Bee Orchid