3. PLANT
CLASSIFICATION
Botony, the study of plants, may not top your list of
interesting subjects.
4. • First, not all green things are plants. Fungi can contain green
pigments. Algae, protozoans, and even some bacteria may
contain enough chlorophyll to make them green.
• Second, not all plants are green. Some have other pigments
which mask the green chlorophyll. Although most plants carry
on photosynthesis with chlorophyll localized in plastids
(autotrophic), there are thousands of heterotrophic plants. What
is the difference between autotrophic and heterotrophic again?
• Third, we cannot overestimate the value of plants to man. The
plant kingdom provides almost all our food.
• Last, plants are a source of inestimable beauty. The quiet of a
lush forest and the delicacy of a soft flower demonstrate much
of God’s plan and creation.
6. Plants:
• Primary source of
food for people and
animals
• Produce oxygen
• help to keep us
cool
7. Plants:
• slow wind speed
• provide a home for
wildlife
• beautify surroundings
• perfume the air
• furnish building
materials and fuel
8. Main Groupings of Plants
• Non-vascular plants: only one phylum of plants lacks
vascular tissues. In this group are the mosses and
similar plants.
• Vascular plants without seeds: Four phyla of plants
have vascular tissues but lack seeds. The best known
phylum is Pterophyta, the ferns.
• Vascular plants with seeds: This group is usually divided
into the two following subgroups: flowering and non-
flowering plants.
9. Non-Vascular Plants: The Mosses
• Non-vascular plants are in phylum Bryophyta which
contains the mosses, liverworts, and a few similar groups.
10. • People often think any small green thing is a moss, even
though it could be grass, fungus, or anything else.
• Most appear as velvety clumps in shaded areas.
• In a clump there actually are many densely packed
individual plants.
• The most obvious part of a moss, the leafy shoot, is 1 in
long and transmits water in small spaces between the
cells in much the same way that a paper towel absorbs
water.
• On the bottom of each shoot is a tangles mass of
rhizoids. They may appear rootlike, but they lack
conducting tissues and therefore are not true roots.
11.
12. Vascular Plants
Without Seeds
• Without Seeds
All plants other than bryophytes have vascular tissues
which conduct water and dissolved minerals through
this plant
• They are unusual in that they do not produce seeds. In
their life cycle they produce spores, a single cell with a
protective coat, which are used to spread the species.
• When released, the powdery fern spores can be carried
by the wind.
• Under proper conditions fern spores germinate and
form a heart-shaped prothallus which is one cell layer
thick.
13.
14. Vascular Plants with Seeds
• Divided into two groups: gymnosperms (three phyla)
& angiosperms (one phylum).
15. Conifers
• Produce seeds in cones.
• Largest phylum of gymnosperms
• Not all cones are like the familiar pine cones and not
all conifers look like pine trees, but the life cycle of a
pine tree is typical.
16. • In spring, pine trees produce two types of cones: pollen cones
and seed cones
• Pollen cones: short-lived, numerous, and small are found
near the tips of branches. They contain the male reproductive
gametes.
• Pollen lands on the open scales of the small, green, upright
seed cone. Usually found on other branches of the same tree.
• The scales close tightly, and in many pines the cones begins
to point downward.
• May not be fertilized until months later, and in some species
they may not develop into seeds for several years.
• When the timing is right and seeds are mature, the scales
open and release the seeds.
17.
18. Angiosperms: Kingdom
Anthophyta: Flowering Plants
• Dominant vegetation on earth today
• So much diversity among the 250,000 species that they
are grouped into nearly 400 different families, based
primarily on floral parts.
• All angiosperms have seeds enclosed in an ovary and
flowers.
• Many angiosperms do not produce colorful blossoms.
Corn tassels and the catkins of oak trees are flowers.
19. Angiosperms
• Divided into two classes: monocots & dicots
• The basic distinction between these two is the number of
cotyledons
• The cotyledons has stored food to keep the embryonic
plant alive while it is in the seed and to supply the sprout
with energy until it can carry on photosynthesis.
• The ovary of a plant is the structure which encloses the
seeds; a mature ovary is a fruit. You can easily identify
apples, cherries, and tomatoes as fruits, but pods of peas
and kernels of corn and wheat are also fruits.
20.
21. Parts Flowers
of a Stems
plant
• Four basic parts Roots
• leaves
• stems
• roots
• flowers Leaves
22. Let’s Look at a Plant…
flower
leaf
stem
What
important
part cannot
be seen?
23. Did you say “Roots”?
What’s the job of the
roots?
• They hold the plant in
place.
• They take in water
from the soil.
• They take in food from
the soil.
24. What does the
stem do?
The stem’s jobs:
• The stem stands
the plant up.
• The stem is the
elevator that takes
the food and water
to the rest of the
plant.
25. The leaf’s job:
• The leaf breathes Why do plants have
in air called carbon leaves?
dioxide and
breathes out
oxygen.
• The leaf takes in
energy from the
sun and turns it
into energy for the This is called
photosynthesis.
plant.
26. The Flower
What
does the
flower
do?
• The flower attracts insects by its color and
smell so insects can pollinate the flower.
• After being pollinated, the flower makes the
seeds.
27. Leaf
• Important function-manufactures food for
the plant by using light energy
• Can turn to catch the sunlight
28. Leaf Margin
• Plants may be identified by the edges, shape
and arrangement of the leaves.
• The leaf edges are known as the margin
29. • A simple leaf is a single leaf
arising from a stem
• Two or more leaves arising from
a common point on the stem is a
compound leaf
30. • A leaf consists of two familiar parts: petiole and
blade
• The petiole is the stem of the leaf
• The blade is the wide portion
31. THE BASICS OF
PHOTOSYNTHESIS
• Almost all plants are photosynthetic autotrophs, as
are some bacteria and protists
– Autotrophs generate their own organic matter through
photosynthesis
– Sunlight energy is transformed to energy stored in the
(b) Kelp form of chemical bonds
31
(c) Euglena
(d) Cyanobacteria
(a) Mosses, ferns, and
flowering plants
32. AN OVERVIEW OF
PHOTOSYNTHESIS
• Photosynthesis is the process by which
autotrophic organisms use light energy to
make sugar and oxygen gas from carbon
dioxide and water
32
Carbon Water Glucose Oxygen
dioxide gas
PHOTOSYNTHESIS
33. Leaf Structure vascular bundle (vein)
xylem (water)
cuticle phloem (sugar)
epidermis
palisades
layer
spongy
layer
epidermis
cuticle stomate guard
cells
Copy this to turn in and use
34. Roots
• Roots can go down 6, 8, 10 feet
• Not all roots are below ground
• Most roots serve to anchor the plants
• They absorb water
• Transport these absorbed substances to
where they are needed in plants.
• Also function as food storage as with carrots,
radishes, and beets.
35. Zone of Maturation - cell differentiation
Protoderm
Ground Meristem
Provascular
Zone of Cell Elongation - cell expansion
Notice how the growing zone has
no root hairs or lateral roots!
Growth among soil particles would
result in shear forces.
Zone of Cell Division - new cells by mitosis
Root Cap - penetration, padding
36. Roots
• Plants such as Poison Ivy and English Ivy have roots that help
them climb trees, walls and sides of buildings
• These are called adventitious roots which appear where
roots are not normally expected.
37. Roots Notes
• Taproot is the main root of a plant and generally
grows straight down from the stem
38. Roots Notes
• Fibrous roots are generally thin, somewhat
hairlike, and numerous. The Fibrous root
system is normally shallow.
39.
40. But shrubs also generally
have some compromise
for uprooting forces…
feeder roots extending
laterally.
In shrubs like this
tea plant (Camellia
sinensis), the root
system will be more
tap root than fibrous
root.
Notice the diameter
of this tap root
compared to this
man’s waist!
41. Tropical soils are nutrient
poor.
Roots must traverse the
surface for minerals, so
roots grow on the surface
(not tap root).
So, to keep this tall baobab
tree standing upright, the
roots grow in diameter but
only in the vertical
dimensions to form ridge
roots…called buttress roots.
My wife here is as large as I
am so you can see these
roots are a meter tall!
These roots inspired gothic
cathedral architects to
design buttress walls.
45. • Stems-support the leaves,
flowers, and fruit.
46. Woody Stems
• Are tough
and winter
hardy. They
often have
bark
around
them.
47. Herbaceous
Stems
• Succulent,
often green,
and will not
survive winter
in cold climates
48.
49. Modified Stems-
bulbs, corms, rhizomes, tubers
bulbs, corms, rhizomes, tubers
• Not all stems are erect, above
ground structure. Some grow
along the ground or even
underground. Some stems have
specialized jobs to perform.
50. Bulbs
• Short stems that are
surrounded by modified
leaves called scales.
• Examples: Easter lilies
and onions
