The formation of floral organs on the meristem follows on the heels of evocation and overlaps with evocation. The conventional angiosperm flower is made up of four whorls of modified leaves constituting the sterile and fertile parts. The sterile parts consist of an outer whorl of sepals that are usually green and enclose the rest of the flower before it opens, and an inner whorl of brightly colored petals that aid in attracting insects and other pollinators. Aggregates of sepals and petals in a flower are known, respectively, as the calyx and the corolla. The fertile organs of the flower directly concerned with sexual reproduction are the stamens, representing the male units, and the carpels (or the pistil, consisting of one or more carpels), representing the female units. Collectively, the stamens and carpels constitute, respectively, the androecium and the gynoecium. These four whorls are produced in acropetal sequence by the floral meristem in the correct numbers of units and are precisely determined according to a blueprint characteristic of each species.


Floral Organ Floral Meristem Homeotic Gene Floral Organ Identity Stamen Primordia 
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Further Reading

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Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • V. Raghavan
    • 1
  1. 1.Department of Plant BiologyThe Ohio State UniversityColumbusUSA

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