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Morphoanatomy of the Morphoanatomy of the Flower Flower

Flower Morphology 2 (updated)

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  • 1.Morphoanatomy of the Flower

2. Lets Review 3. Parts of a Flower Pedicel -the stalk of an individual flower 4. Sepal --one member of the outermost whorl of a flower. Collectively, the sepals make up the calyx. The sepals may be free or fused. 5. Petal --one member of the second whorl of a flower. Collectively, the petals make up the corolla. The petals may be free (the flower then termed polypetalous) or fused into one piece (the flower then termed sympetalous). 6. Perianth--the calyx and corolla together 7. Corolla CalyxCollective term for sepals 8. Other terminologies: Complete flower when calyx, corolla, androecium and gynoecium are present Incomplete Flower when one of the four whorl missing. Unisexual flower androecium (staminate) or gynoecium (pistillate) any one of them are present in the flower. Bisexual flower both male and female are present in a flower. 9. Other terminologies Monoecious plant when both male and female flowers are present on the same plant. 10. Other terminologies Dioecious plant When male and female flowers are present on separate plant. 11. Flower Symmetry An assessment of the presence and number of mirror-image planes of symmetry 12. Flower Symmetry Actinomorphic/ Radial / Regular - When flower is divided by any vertical plane into two equal halves 13. Zygomorphic / Bilateral - when flower is divided into two equal halves only by one vertical plane. 14. Assymetrical / Irregular When flower cannot be divided into equal halves from any plane. 15. Internodal Elongation in Flower 16. Internodal elongation in flower 1. Anthophore = internode between the calyx and corolla. 17. 2.Androphore = internode between the corolla and androecium 18. 3. Gynophore = internode between corolla and gynoecium 19. 4. Gynandrophore or Androgynophore When both androphore and gynophore both conditions are found in the same flower 20. 5. Carpophore Elongation of thalamus beyond carpels 21. Variation of Androecium 22. Stamen--one member of the whorl of male sex parts. The part of the flower that produces pollen. This consists of two parts. The anther or top of the stamen actually produces the pollen. the anther is held aloft by a filament which is like a stem of the stamen. 23. Each stamen consists of a filament and anther, where pollen is produced. Collectively, the stamens make up the androecium androeciumTypes of Stamens 1. Tetradynamous - refers to four long and two short stamens in one flower 24. 2. Monadelphousrefers to stamens united by the filaments into one column 25. 3. Diadelphous--refersto stamens united by the filaments into two groups--often 1 in one group and 9 in another Corydalis flavula 26. Carpel - one member of the whorl of female sex parts. - Collectively, the carpels make up the gynoecium. - Each carpel consists of an ovary connected to a stigma by a style. - The stigma is receptive to pollen. Within the ovary, on the placentae (sing., placenta) are one or more ovules, which will mature into seeds. - The open spaces inside the ovary are called locules or cells. The dividing walls are called septa. 27. Carpel = inserted above the stamens, = uppermost floral organ = consist of Stigma, Style and Pistil which is collectively called Gynoecium 28. Stigma - Tip of the carpel, receptive to pollen Ovary - Base of the carpel, contains Ovules Style - Connects the Stigma to the Ovary 29. Types of Carpels 1. Apocarpous - The flower is said to have many simple pistils - A gynoecium of many separate carpelsCrassula 30. Magnolia 31. 2. Syncarpous = A gynoecium of many fused carpels = The flower is said to have a compound pistilSaxafraga 32. Poppy 33. 3. monocarpous In the very center of the flower is a single carpel. A carpel is the basic unit of a gynoecium. This flower only has one carpel, and flowers like this are said to have a monocarpous gynoecium. 34. 4. Unicarpellate - gynoecium with only one carpel - The flower has a simple pistil 35. hypanthiumA hypanthium (= floral cup) is a structure derived by the adnation of the perianth bases and stamens. It can be variously shaped. This is a line drawing corresponding to a longitudinal section of a Prunus (cherry) flower. 36. Ovary Position 1. Hypogynous--The flower is hypogynous if the ovary is situated above the calyx and there is no floral cup around it. The ovary is superior. 37. 2. Perigynous -The flower is perigynous if the ovary is situated within (and free from) a floral cup or hypanthium. The ovary is superior. When the perianth and the stamens arise from a hypanthium that is NOT adnate to a superior ovary, the insertion is said to be perigynous, as in this longitudinal section of a flower of black cherry Prunus serotina. 38. 3. Epigynous --The flower is epigynous if the ovary is situated below the calyx. The ovary is inferior. (In the graphic example, the calyx is pink and the flower hangs upside down.) 39. Additional Terminologies Bracts = specialized leaves present in axis of flower. 40. Involucre = the whorl of bract surrounding peduncle 41. Involucel = group of bracteole 42. Spathe- in flowers when large bract completely encloses whole inflorenscence 43. Petaloid bract in flowers when large bract of flower is greater than the size of flower and these of various colour. 44. Glumes =small,dry scaly bracts 45. Calyx first whorl of flower Duration of sepals 46. Caducous =Sepals fall just at the time of opening of flower bud. poppy Deciduous =sepals fall after pollination. mustard Persistant = If sepals don't fall and remain attached to fruit. 47. Corolla The second whorl of flower Fusion of Corolla Polypetalous = petals are free Gamopetalous = the corolla is fused 48. polypetalousgamopetalous 49. Assignment Draw and label the types of a. Polypetalous b. Gamopetalous Short bond paper Submitted on Monday 50. Solitary --just one flower on the peduncle 51. Inflorescence An inflorescence may be defined as a cluster of flowers, all flowers arising from the main stem axis or peduncle: 52. Inflorescence An inflorescence may be defined as a cluster of flowers, all flowers arising from the main stem axis or peduncle: 53. cyme 54. Different types of inflorescences A catkin - a spike-like inflorescence (i.e. the flowers do not have a pedicel and the main axis is elongated and unbranched) which has only male or female flowers. They occur in many woody trees such as the hazelnut and the willow. A willow catkin (Salix sp) 55. Left: Male (staminate) catkin from the white mulberry (Morus alba), a fruitless variety commonly planted as a shade tree in southern California. Right: An individual male flower containing four stamens, each with an anther and a filament. At the base of each filament is a fleshy green sepal. 56. Female flowers consist of single pistil tightly enveloped by four inconspicuous sepals. Each carpel or pistil (also referred as a gynoecium) consists of a forked stigma, a short style and a spherical ovary. Each ovary (carpel) becomes a drupelet and the ripened cluster of drupelets (syncarp) is called a multiple fruit. In the aggregate fruit of a blackberry, all the drupelets of the cluster (syncarp) come from a single flower 57. Spadix - is the characteristic inflorescence of the remarkable arum family (Araceae). - It consists of a thickened, fleshy axis (spike) bearing clusters of sessile, apetalous, unisexual flowers. - 58. The small unisexual flowers are packed together along the lower region of an erect, phallus-like central spike, typically with male flowers above the female. - The upper region of the spadix is usually devoid of flowers. - Male (staminate) flowers consist of numerous stamens packed together, 59. - while female (pistillate) flowers consist of numerous individual pistils. - Individual flowers are reduced to a single stamen or pistil (gynoecium). - The spadix emerges from a vaseshaped or funnel-like modified leaf or spathe which is often brightly colored. - The spadix of some arums emits a putrid odor that attracts carrion flies for pollination. 60. The bizarre Malaysian Amorphophallus paeoniifolius. An enlarged, inflated, flower-bearing spadix protrudes from the vase-shaped spathe. Clusters of yellow male flowers (stamens) can be seen above the whitish stigmas of female flowers (pistils). 61. raceme - This inflorescence has an unbranched main axis and all the pedicels of the flowers are more or less the same length. 62. Other racemeSweet pea (Lathyrus odoratus)Chinese hat (Holmskioldia sp.) 63. umbel - The peduncle of this type of inflorescence bears all of the pedicels at its apex.Hydrangea (Hydrangea macrophylla)Lantana (Lantana sp) 64. compound umbel - The peduncle bears a number of primary pedicels at its apex. These do no bear flowers but a number of secondary pedicels at their apices which in turn bear the flowers.Frangipani (Plumeria rubra) 65. spike - This inflorescence type has a long, unbranched main axis which bears flowers which have no pedicels or very short pedicels.Silver oak (Grevillea robusta) 66. Q u i v e r t r e e ( A l o eGladiolus (Gladiolusd i c h o t sp.) m a )u Q i u v i Quiver e v r e r t r t e r e e e ( A ( l A o l e o e d i d c i h c o h t o m t a m ) atree (Aloe dichotma)Red hot poker (Kniphofia sp.) 67. head (capitulum) - which do not have pedicels - are grouped together on the top of a peduncle which may be flattened or rounded. - Daisies (Asteraceae) are a good example - outer flowers may have one very large petal - In other families the whole inflorescence may be surrounded by bracts e.g. the Proteas. - This gives the impression that the whole structure is a single flower but it may in fact be hundreds of flowers grouped together. 68. Examples:King protea (Protea cynaroides)Daisy species 69. Mimosa sp.Pincushions (Leucospermum sp.) 70. A corymb - The main axis of this inflorescence type is elongated and unbranched as in a raceme, but the pedicels of the flowers are of unequal length so that the entire structure appears flat-topped. Examples include hawthorn, the apple and dogwood. Crataegus calpodendron 71. Hydrangea corymb (group of flowers displayed as a disc) hawthorn 72. Difference of corycomb, cyme and umbel 73. Spikelet -like a spike, but with the flowers and inflorescence subtended by specialized bracts. Usually applied to the grass family (Poaceae) 74. Verticil or Whorl-the flowers are borne in a tight circle at each node 75. Panicle --the main axis has branches which are in turn rebranched 76. Inflorescence Types 77. The End