Flowers, Inflorescences & Fruits

1. Flowers, Inflorescences & Fruits

2. Flowers, Inflorescence & Fruits • Floral characteristics are the most commonly features to identify plants • Much more reliable than vegetative characteristics

3. Flower • A typical flower is a stem tip bearing two whorls of appendages that are sterile and two that are fertile • All four whorls are considered to be modified leaves

4. Flower • Typical flower • 4 main parts

5. Flower • Sterile parts • Sepals: protect flower bud • All sepals called calyx • Petals: pretty parts that attract pollinators • All petals called corolla • Calyx and corolla make up the perianth

6. Flower • Fertile parts • Stamens • Male reproductive structures • Anther • Filaments • All stamens called androecium

7. Flower • Fertile parts • Carpel • Stigma • Style • Ovary • All carpels called the gynoecium

8. Presence or Absence of PartsTerms Applied to Individual Flowers • Complete: has all the floral parts • Sepals • Petals • Stamens • Carpels

9. Presence or Absence of PartsTerms Applied to Individual Flowers • Incomplete: missing one of more of the floral parts Ginger flower missing petals

10. Presence or Absence of PartsTerms Applied to Individual Flowers • Perfect (=bisexual): flower with both stamens and carpels Grape flower with stamens and carpels

11. Presence or Absence of PartsTerms Applied to Individual Flowers • Imperfect (=unisexual): missing stamens or carpels, but not both Staminate flower; anthers only

12. Presence or Absence of PartsTerms Applied to Individual Flowers • Staminate (=male): unisexual flower with just stamens present Imperfect staminate flower; stamens only, no carples

13. Presence or Absence of PartsTerms Applied to Individual Flowers • Carpellate (=female): unisexual flower just carpels present Imperfect carpellate flower; carpel only; no stamens

14. Presence or Absence of PartsTerms Applied to Plants with Imperfect Flowers • Monoecious: any plant that has both staminate and carpellate flowers

15. Presence or Absence of PartsTerms Applied to Plants with Imperfect Flowers • Dioecious: plant that has either staminate flowers or carpellate flowers, but not both

16. Insertion of Floral Parts • The position of the gynoecium in relation to all the other floral parts is the basis for for the terminology used in keys and taxonomic descriptions

17. Insertion of Floral Parts • Hypogynous: the sepals, petals, and stamens are inserted under the carpel • Ovary is said to be superior to all the other floral parts

18. Insertion of Floral Parts • In a perigynous flower, the sepal, petals, and stamens are fused together to form a cup called the hypanthium • The gynoecium sits inside the cup but is not fused to it • Ovary is said to be superior to all the other floral parts

19. Insertion of Floral Parts • In a epigynousflower, the sepals, petals, and stamens arise from a point above the ovary • Ovary is said to be inferior to all the other floral parts

20. Floral Symmetry • Actinomorphic (=radial): cutting the flower in any pane produces a mirror image

21. Floral Symmetry • Zygomorphic (=bilateral): can cut the flower in only one plane to get a mirror image

22. Inflorescence Types • An inflorescence is an arrangement of one or more flowers on a floral axis

23. Inflorescence Types • Inflorescence type determined by: • Number of flowers • Positional relationships • Degree of the development of their pedicels • Nature of their branching pattern

24. Simple Inflorescences • Terminal: flower at the tip of a stem • Also known as solitary Scarlet rose-mallow (Hibiscus coccineus)

25. Compound Inflorescences • Two or more flowers per inflorescence

26. Compound Inflorescences • Spike: elongate inflorescence; flowers are sessile, dense, or remote from one another Spiked blazing star (Liatrisspicata)

27. Compound Inflorescences • Catkin: a pendant or erect inflorescence in which unisexual flowers lack petals and are hidden by scaly bracts

28. Compound Inflorescences • Raceme: an elongate inflorescence of pedicellate flowers on an unbranched rachis Bluebonnet (Lupinustexensis)

29. Compound Inflorescences • Umbel: a flat-topped or somewhat rounded inflorescence in which all of the pedicels arise from a common point at the tip of the peduncle Butterfly weed (Asclepias sp.)

30. Compound Inflorescences • Corymb: a flat-topped or somewhat rounded inflorescence in which the pedicels of varying length are inserted along the rachis

31. Compound Inflorescences • Panicle: a much-branched inflorescence with a central rachis which bears branches which are themselves branched

32. BREAK