1. PLANTS

2. Plant Origins: The Beginnings
Earth formed
4.5 bya
Oldest fossils
bacteria-like prokaryotes
~3.5 bya
Oldest autotrophs
Cyanobacteria
~3.4 bya
O2 levels increase to modern levels (~21%)
~2.7 bya – ~500 mya
Oldest eukaryotes
~2.1 bya
Oldest algae
~1.5 bya
O3 level protection enables diversification
~450 mya

3. Plant Origins: Land! Land plants (mosses) Gymnosperms Cycads ~300 mya
Bryophytes
~420 mya
Gymnosperms
Cycads
~300 mya
Ferns
~400 mya
Angiosperms
~240 mya

4. Fern fossil, ~300 mya
Bryophyte fossil, ~420 mya

5. ~75 mya cycad leaf, San Diego CA
Oldest flower fossil, in amber, Myanmar
~100 mya

6. Evolution of the Seed
Natural selection over ~100 my  development of seed-bearing plants
Developing embryo nourished & protected
can wait a long time to germinate when conditions are good
a dormancy period
Seeds dispersed more widely than spores
enclosing them in a bribe (fruit)
having animals move them

7. Seeds > Spores Spores Seeds Short lifetime
Thinner walled and more vulnerable to pathogens and damage
Seeds
More durable; longer lifetime
Embryo better protected

8. Flowering plants Angiosperm systems Root system Below or above ground
Shoot system
leaves, buds, flowers, fruit borne
on stems which may be branched

9. Angiosperm groups Monocots grasses, lilies, palms, orchids Dicots
Mangos, Chinese hat plant, peanuts

10. SHOOT SYSTEM ROOT SYSTEM
apical meristem
beginning leaves
terminal bud
flower
branch
lateral bud
SHOOT SYSTEM
leaf
stem
branch
roots
Figure: 17-01
Title:
The structure of a typical flowering plant.
Caption:
ROOT SYSTEM
taproot
root hairs
root cap

11. Leaf Function P ___________________
Absorption of nutrients via modified leaves
Ex. c_________________ p__________
Ex. b____________________

12. Root Functions ”AUNTS” Anchorage Uptake of water/nutrients
Nutrient storage
Transport of water/nutrients
Storage of sugars, nutrients, water

13. branch roots taproot ROOT SYSTEM root hairs root cap Figure: 17-01b
Title:
The structure of a typical flowering plant.
Caption:
(b) Root system. The structure of a typical flowering plant.
root hairs
root cap

14. Quaking Aspen: 47ha of 47K male trunks @ 6,500 tons
4/3/2019
FTBG Summer Botany Inservice

15. Stem Tissues Cortex & Pith
4/3/2019
Cortex & Pith
Support, storage in soft, spongy (non-woody) tissue
Ex. herbaceous plants (tomatoes)
Some photosynthesis

16. FTBG Summer Botany Inservice
Vascular Tissue
Function =
Xylem transports water, nutrients & (stored sugars) up from roots
Sapwood = soft, new xylem
Ex. Balsa wood
Heartwood = oldest xylem, no transport due to ____________________________ often dark color
Phloem transports products of photosynthesis & hormones down from leaves, stems
Vascular cambium =
4/3/2019
FTBG Summer Botany Inservice
Waste dump clogs the xylem

17. Xylem Sapwood = soft, new xylem Heartwood = oldest xylem,
Xylem transports water, nutrients & stored sugars up from roots
XY - HIGH
Sapwood = soft, new xylem
Ex. Balsa wood
Heartwood = oldest xylem,
No transport of water due to accumulation of residue of once-living cells.
The heartwood is often dark color
4/3/2019
Waste dump clogs the xylem

18. Phloem
Phloem transports products of photosynthesis & hormones down from leaves, stems
PHLO – FALLS
Oldest phloem  “bark”
Can be smooth, rough, fissured, corky, spongy, brightly colored, peeling, spiky/spiny/prickly, etc.

19. Vascular Cambium
The vascular cambium is a plant tissue located between the xylem and the phloem in the stem and root of a vascular plant.
It is the source of both the secondary xylem growth (inwards, towards the pith material at the center of the plant) and the secondary phloem growth (outwards [to the bark, rough or smooth, of the plant]).
It is a cylinder of unspecialized meristem cells that divide to give new cells which then specialize to form secondary vascular tissues.

20. Meristem “stem cells”
Meristem cells give rise to differentiated cells  become mature leaves or trunks of trees
Site of active cell division  growth of roots & shoots

21. vascular bundle xylem vascular cambium phloem Figure: 17-11d Title:
The structure of a young dicot stem.
Caption:
(d) Vascular bundle. In cross section, vascular tissue forms a ring of vascular bundles in dicots.
phloem

23. Flowers & Fruit
Angiosperm success due to evolution of flowers and fruit
Flowers’ functions = A major advantage of flowers is that they have allowed angiosperms to use other organisms to move their pollen about.
Bees, bats, birds and others all transport pollen. They are attracted to flowers by the nectar and pollen [bribes] provided by the plant and when they visit multiple flowers they move pollen from one to the next
Flowers’ bribes =
Fruit functions =
A major advantage of flowers is that they have allowed angiosperms to use other organisms to move their pollen about.
Bees, bats, birds and others all transport pollen. They are attracted to flowers by the nectar and pollen [bribes] provided by the plant and when they visit multiple flowers they move pollen from one to the next

24. FTBG Summer Botany Inservice
6/16/14
FTBG Summer Botany Inservice

25. Flower Parts FEMALE MALE Pistil Stamen Non-reproductive structures
Stigma
Style
Ovary
Ovule
MALE
Stamen
Filament
Anther
Non-reproductive structures
Petals
Sepals
4/3/2019
FTBG Summer Botany Inservice

27. Pistil
The female part of the flower is called the pistil (or carpel) and is composed of:
Stigma – the sticky, receptive tip of the pistil that is responsible for catching the pollen
Style – the tube-shaped connection between the stigma and ovule (it elevates the stigma to help catch pollen)
Ovule – the structure that contains the female reproductive cells (after fertilization, it will develop into a seed)

28. Stamen
The male part of the flower is called the stamen and is composed of:
Anther – pollen producing organ of the flower (pollen is the male gamete of a flowering plant)
Filament – slender stalk supporting the anther (makes the anther accessible to pollinators)

29. Non-reproductive structures
In addition to these reproductive structures, flowers possess a number of other support structures:
Petals – brightly colored modified leaves, which function to attract pollinators
Sepal – Outer covering which protects the flower when in bud
Peduncle – Stalk of the flower