1. Biology – 328 Lab
Plants and People

2. Objective Understanding origin of flowers, its morphology and anatomy
To study flowers based on
Types of pollination
Presence of floral whorls
Presence of sexes
Line of symmetry
Sexual expression
Position of ovary
To study different types of inflorescences

3. Background Origin – Modified shoot Floral Morphology Calyx (sepals)
Corolla (petals) - 3’s in monocots and 4’s or 5’s in dicots)
Perianth (calyx + corolla)
Gynoecium (pistil- stigma, style, ovary)
Androecium (stamen- anther, filament)
Receptacle

5. Floral anatomy Locules – Open space inside ovary
Carpels – Basic developmental unit
Apocarpous (carpels not fused)
Syncarpous (carpels fused)
Pistil
Simple – Unicarpellate (1 carpel)
Compound – Syncarpellate (2 or more carpels FUSED)

8. Types of flowers Based on pollination Entomophily (insect)
Anemophily (wind)
Based on presence of floral whorls
Complete flower - All 4 floral whorls present
Incomplete – Not all 4 floral whorls present
Based on presence of sexes
Perfect – Both sexes present
Imperfect – Not both sexes present

9. Based on line of symmetry
Actinomorphic (regular)– more than one plane of symmetry
Zygomorphic (irregular)– One plane of symmetry
Based on sexual expression
Monoecious – “One house” (male and female part present in the same flower in the same plant or different flowers in the same plant)
Dioecious – “Two house” (male and female flowers in different flowers in different plants

10. Based on ovary position
Hypogynous (superior ovary) – Floral whorls arranged below (=hypo) ovary (=gynous)

11. Epigynous (Inferior ovary) – Floral whorls arranged above (epi) ovary (=gynous)

12. Perigynous (superior ovary) – Floral whorls arranged around (=peri) overy (=gynous). Presence of well developed HYPANTHIUM (cup) made of receptacle and bases of sepals, petals and stamen

14. Types of inflorescences
Raceme – Unbranched inflo. with pedicel and indeterminate (young flowers on top).
Eg. Orchid, Milkwort

15. Spike – Same as receme but no pedicel (sessile flowers)
Eg. Gladious, Hyacinth

16. Catkin/Ament - Same as spike, but unisexual
Eg. Oak, Pecan, Birch, hickory, willow

17. Umbel – All pedicels arise from a common point
Eg. Onion, Garlic

18. Compound Umbel – Group of umbels whose peduncles arise from same point
Eg. All members of Apiaceae (carrot family)
Panicle – Inflorescence which branches and rebranches. For eg. Yucca, Lilac, Wisteria

19. Head/Capitulum – Dense arrangement of sessile flowers on a common receptacle
Eg. Sunflower, Daisy, Aster, Thistle

20. Today’s Lab
Carefully EXAMINE all floral material provided using the following exercise and questions as a guideline.  To gain an ultimate familiarity with floral morphology, compare the material against descriptions and definitions in your lecture notes or textbook.  Become familiar with cross and long sections.
1.  Flowers are arranged in groups called inflorescences.  We will examine some inflorescences particular to certain families later in the semester.  For now, know what an inflorescence is and which one we looked at today.
2.  DRAW a longitudinal section of a typical flower labeling the following parts:  receptacle, calyx, sepals, corolla, petals, perianth, pedicel, ovary, ovule, style, stigma, pistil, gynoecium, anther, filament, stamen, and androecium.

21. Today’s Lab
3.  EXAMINE by dissection the floral material provided making long and cross sections of the flower and its parts.  On a separate sheet of paper, SKETCH the flowers and label the parts.  Then, FOR EACH FLOWER, answer the following questions:
Is the flower actinomorphic (regular) or zygomorphic (irregular)?
How many sepals are present?  Petals?  Stamens?  Carpels?  To count carpels, count the style branches and/or count the zones of placentation by cross- sectioning the ovary.
Is the ovary inferior or superior?
Is the flower from a monocotyledonous or dicotyledonous plant?
Is the flower perfect (both sexes present) or imperfect?  Complete (all four floral whorls) or incomplete?

25. Summary Today’s Lab Floral Origin, morphology and anatomy
Different types of flowers and inflorescence
Next week’s lab – Fruits
Quiz on Flowers