Arrangement of flowers1.Calyx Calyx is a cup shaped structure. It is found at the bottom of all the other parts. It consistof sepals. Sepals are similar to small green leaves. Colourful sepals can be in some flowers. Function of the calyx is the protection of tender theflower bud. Photosynthesis takes place in green in coloured sepals Colourful sepals are important to attract insects forpollination
Image for calyx flowersMusandas Sesbenia Tribulus Rose Musandas Muntingia
2.Corolla Within the calyx are the whorl of floral leavescalled petals, together and forming the corolla. It is the most beautiful and attractive part of theflower. The corolla protects the internal parts of flowerand also helps to attract insects for pollination. The corolla is colourful in majority of flowerswhich are pollinated by insects Corolla shows diversity in colour and shape
In most of the flowers which bloom during thenight, the corolla is white in colour and the flowers arescented. This is also important to attract insects for pollination Coral jasmine Getapichcha Kadupul
3.Androecium Androecium is the male part of a flower. It is the whorl of floral leaves found inside the corolla. Androecium consists of stamens. A stamen consists of the another and the filament. The function of the androecium is to produce and release pollen grains. Stamens of flowers can be independent or connected to the petals.
Image for androecium flowersBrassica Shoe flower TorneiaGloriosa Passion fruit Calotropis
4.Gynoecium or pistil Gynoecium or pistil is the female partof a flower. It is the innermost part of a flower . It consists of three parts namelystigma, style, and ovary. The stigma is situated at the top andthe ovary is situated at the base. The style is a tube like structure whichconnects the stigma and the ovary. Ovules can be seen in the ovary. After pollination the ovary becomesthe fruit and the ovules become seeds.
5.Bisexual flowers If the both gynoecium (pistil) and the androecium are present in a flower it is called a bisexual flower. Examples for bisexual flowers. Blue lily Shoe flower Sesbenia Casealpinia
6. Unisexual flowers In some flowers only one of these two parts are present. Such flowers are called unisexual flower. Examples for unisexual flowers. Coconut flowers
Symmetry of flowers1. Radially symmetrical flowers or an actinomorphic flowers. If a flower can be divided into two similar halves by cutting vertically through any one of its axis which passes through the centre, such flowers are known as radially symmetrical flowers or an actinomorphic flowers.
2. Zygomorphic flowers Some flowers can be divided intotwo similar halves by cutting alongonly one symmetrical axis. These flowers can be known asbilaterally symmetrical flowers orzygomorphic flowers.
Image for Zygomorphic flowers Salvia Leucus zeylaniea CrotolariaThunbergia Sesbenia Caesalpinia
3. Asymmetrical flowers Some flowers cannot be divided into twosimilar halves by cutting along any axis. These flowers are known as irregular orasymmetrical flowers. Species of cactus Examples for such flowers.Species of cactus Species of cactus Species of cactus
Structure of flowers There are some standard methodsto describe the structure of flowers. They are Whole flower Half flower Floral diagram
1. Whole flower By observing a flowerexternally we can studystructure of the flower. To observe thecolour, nature, its parts andtheir position in the flower bythe naked eye one has toobserve a whole flower
1. Half flower To observe the parts of a flowermore clearly we can separate a flowerinto two similar halves through asymmetrical axis of the flower Because some parts which cannotbe seen by observing the flowerexternally clearly seen in a halfflower. Therefore a half flower is used todescribe the structure of a flower. Half flower can be depicted by aline.
3. Floral diagram A transverse section drawn sothat all the parts of the flower arein the same level is called a floraldiagram. This is similar to a diagram of aflower drawn as seen from the top. To draw a floral diagram themain axis of the tree should placedthe anterior side and the bractshould placed to the posterior side. Position of a flower in the tree Floral diagram of flower
1) If the both gynoecium and androecium are present in a flower it is known as Corolla of the flowers Unisexual flowers Calyx of the flowers Bisexual flowers
2)If a flower can be divided into two similar halves by cutting vertically through any one of its axis which passes through the center such flowers are known as Androecium Zygomorphic flowers Actinomorphic flowers Asymmetrical flowers
3)Example for asymmetrical flower isOrchidSesbeniaCactusRose
4)Example for actinomorphic flower is Pumpkin Cannon ball tree Coconut flower Lotus
3)Example for zygomorphic flower isCaesalpiniaShoe flowerPassion fruit flowerGloriosa