1. Presentation created by Danielle Sherdan
BOT3015L Biology of Flowering Plants: Reproduction Flowers and Pollination
The material we will discuss today is also presented in the lecture notes, Angiosperm Morphology and Flowering. Reproduction is vital for evoultion.
Presentation created by Danielle Sherdan
All photos from Raven et al. Biology of Plants except when otherwise noted

2. Today Introducing angiosperms, flower structure and function
Pollination
Evolutionary trends in floral structure
Inflorescences
Monocots and dicots
Introducing angiosperms, flower structure and function
Pollination
Evolutionary trends in floral structure
Inflorescences
Monocots and dicots

3. Flowers are distinguishing characteristics of angiosperms
All fruits come from flowers
Angion=vessel
Sperma=seed
Angiosperms have seeds contained in a vessel (developing ovary)
Saguaro cactus
Cherry
Example flowers collage. Define angiosperm
Apple
Cattleya orchid
Sunflowers

4. How are these functions important for the survival of species?
Flowers
What are the functions of flowers?
How are these functions important for the survival of species?
Flower dissection
Honeysuckle

5. Alternation of Generations generalized plant life cycle
In angiosperms, gametophytes are borne within the reproductive structures of the flower; thus flowers are important when discussing evolution of angiosperms

6. Flower dissection a guided tour
Notice the arrangement of the floral parts

7. Arrangements of floral organs
Primitive
Advanced
Spiral arrangement of floral organs.
Stamens
Sepals
Petals
Carpels
Arrangement of floral organs in whorls.

8. Flower dissection a guided tour
What are the functions of these floral parts?
Note that the petals are inserted after the sepals

9. Flower dissection a guided tour
What are the functions of the stamens?
stamen
Hint: collectively, the stamens are termed the androecium (andro=male, ecium=house).
We will discuss the microgametophyte next week

10. The stamens of most grasses (left) and the paper birch (right) are easily blown by wind.
The flowers of most grasses do not have showy petals, why?

11. Flower dissection a guided tour
Ovary, ovules (within ovary), style, and stigma comprise the carpel (megasporophyll)
stamen
What are the functions of the carpel?
We will discuss more about the megagametophyte next week

12. Alternation of Generations generalized plant life cycle
Requires pollination
In angiosperms, gametophytes are born within the reproductive structures of the flower; thus flowers are important when discussing evolution of angiosperms

13. Today Introducing angiosperms, flower structure and function
Pollination
Evolutionary trends in floral structure
Inflorescences
Monocots and dicots

14. Pollination
In angiosperms, movement of the microgametophyte (pollen grain) to the megagametophyte in the ovule of the carpel
How does a sessile organism, the microgametophyte in the case of angiosperms move?
Vectors
In the following discussion, notice the co-evolution of flowers and their biotic vectors

15. Some plants make big investments in attracting animal pollination vectors
Nectar
On the right, perianth segments modified onto nectar-filled tubes that are inaccesible to most animals, except their pollinators, hummingbirds.
Notice the pollen on the hummingbird’s forehead and the stigma that touches it as he feeds

16. Seat bee gathering pollen from the stamens of a cactus flower
Some plants make big investments in attracting animal pollination vectors
Pollen
Seat bee gathering pollen from the stamens of a cactus flower

17. Some plants make big investments in attracting animal pollination vectors
Drugs (Intoxication)
Flies find the chemical inside the pouch-like petal to be attractive and intoxicating. As they exit the pouch, pollen is deposited on them.
Cypridium sp.
Koning, Ross E Pollination Adaptations. Plant Physiology Information Website. ( ).

18. Some plants make big investments in attracting animal pollination vectors
Prospect of Sex (pseudocopulation)
photonature-pvd.chez.tiscali.fr/ ophrys.htm
Ophrys bécasse Charente
Ophrys speculum

19. Plants that rely on wind make big investments in pollen
Notice the stigmas that fan out to easily catch pollen
birch
grass

20. Pollination Biology movie

21. Today Introducing angiosperms, flower structure and function
Pollination
Evolutionary trends in floral structure
Inflorescences
Monocots and dicots

22. Evolutionary Trends in Floral Structure
1. Reduction in number of parts

23. Perfect and Imperfect flowers
From
Outlaw lecture

24. Evolutionary Trends in Floral Structure
Reduction in number of parts
2. Cyclic arrangement (vs. spiral)
3. Fusion of organs

25. Fusion of floral parts
Outlaw lecture notes
Angel trumpet has fused petals that form a floral tube

26. Notice the stamens fused to the carpel of this hibiscus flower
Fusion of organs
Danielle Sherdan
NE Tallahassee, FL
Notice the stamens fused to the carpel of this hibiscus flower

27. Fusion of floral parts Superior and Inferior ovaries
Ancestral
Derived
Superior ovary (primitive)—note typical appearance of order of insertion of floral parts.
Inferior, floral tube fused to ovary wall, making ovary appear to arise below other floral parts.
Superior, parts still appear to arise in normal order.

28. Evolutionary Trends in Floral Structure
Reduction in number of parts
2. Cyclic arrangement (vs. spiral)
3. Fusion of organs
4. Away from marginal placentation

29. Seeds attached to margin of single carpel
Placentation
Within each ovule, double fertilization, a distinguishing characteristic of angiosperms, produces the zygote and endosperm.
Marginal
Seeds attached to margin of single carpel
Primitive
Advanced
Fusion of carpels
Parietal
The ovary develops into the fruit, another distinguishing characteristic of angiosperms
Axile
Free central

30. Evolutionary Trends in Floral Structure
Reduction in number of parts
2. Cyclic arrangement (vs. spiral)
3. Fusion of organs
4. Away from marginal placentation
5. Away from regularity e.g. toward bilateral symmetry over radial symmetry

31. Bilateral and Radial Symmetry
This wintergreen displays radial symmetry, which is primitive, but fused carpels, which is derived
This orchid, an advanced monocot, displays bilateral symmetry

32. Today Introducing angiosperms, flower structure and function
Pollination
Evolutionary trends in floral structure
Inflorescences
Monocots and dicots

33. Inflorescences Groups of flowers in particular arrangements
Some examples
Lupine

34. Inflorescences Groups of flowers in particular arrangements
What is a fitness advantage of having inflorescences?
What is a fitness disadvantage of having inflorescences?

35. Inflorescences Groups of flowers in particular arrangements
Notice that these composites display many evolutionarily advanced characteristics

36. Today Introducing angiosperms, flower structure and function
Pollination
Evolutionary trends in floral structure
Inflorescences
Monocots and dicots

37. Monocots and Dicots the two major groups of angiosperms
Monocots and dicots have several differentiating characteristics
Number of cotyledons
Observe today
Leaf venation
Number of flower parts
Seed structure at maturity
In your lab notebook, create a table to contrast these traits in monocots and dicots
Function of cotyledons
Root structure
Secondary growth in shoot
Arrangement of vascular bundles