Actinomorphic

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  • Topic: Plant morphology, Ranunculaceae, Floral symmetry
  • Pages : 2 (387 words )
  • Download(s) : 198
  • Published : November 9, 2011
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Actinomorphic
Most flowers are actinomorphic ("star shaped", "radial"), meaning they can be divided into 3 or more identical sectors which are related to each other by rotation about the centre of the flower. Typically, each sector would contain one petal, one sepal and so on. It may or may not be possible to divide the flower into symmetrical halves by the same number of longitudinal planes passing through the axis: Oleander is an example of a flower without such mirror planes. Actinomorphic flowers are also called radially symmetrical or regular flowers. Other examples of actinomorphic flowers are the lily (Lilium, Liliaceae) and the buttercup (Ranunculus,Ranunculaceae). -------------------------------------------------

[edit]Zygomorphic
Zygomorphic ("yoke shaped", "bilateral") flowers can be divided by only a single plane into two mirror-image halves, much like a yoke or a person's face. Examples are orchids and the flowers of most members of the Lamiales (e.g., Scrophulariaceae and Gesneriaceae). Zygomorphic flowers generally have petals of two more different shapes, sizes, and colors. Least commonly, flowers may be asymmetrical; they cannot be divided into two identical or mirror-image halves on any plane. Such flowers are typical of most members of the Zingiberales, such as cannas and various gingers. In most cases, different kinds of floral symmetry are linked to particular pollinators. -------------------------------------------------

[edit]Differences
Actinomorphic flowers are a basal angiosperm character; zygomorphic flowers are a derived character that has evolved many times.[1] Some familiar and seemingly actinomorphic flowers, such as those of daisies and dandelions (Asteraceae), are actually clusters of tiny zygomorphic flowers arranged into a radially symmetric inflorescence. -------------------------------------------------

[edit]Peloria
Peloria or a peloric flower refers to an aberration...
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