Flower - A fascinating structure of Flowering plant

 

Flower is a special reproductive structure found in Angiospermic plants. It develops in the axil of a small  leaf-like structure called bract. If a flower bears bract then it is called bracteate or it is absent called ebracteate. The stalk of a flower is called a pedicel. A pedicel bearing flower is called a pedicellate. If the pedicel is small the flower is sub sessile and if the pedicel is absent then the flower is sessile.

Essential and Non essential organ in flower 

The tip of the pedicel has a swollen structure called thalamus. It bears sepals, petals, stamen and carpel. Out of these stamen and carpel are essential organs because they take part in reproduction. Sepal petals are not take part directly in reproduction so they are a non essential organ of the flower.

Complete and Incomplete flower 

A complete flower has all four types of floral organ. If any floral organ like sepals or petals or stamens or carpels is absent

Then the flower is said to be incomplete . 

Staminate and pistllate  flower 

If a flower has both essential organs then it is perfect. A perfect flower may be hermaphrodite or bisexual. If a flower has only one type of essential organ it is called  unisexual or imperfect. A flower is staminate when only stamen is present and flower is pistillate when only pistil is present. The flower is neuter if all essential organs are absent or non functional.

Monocious and Diocious Plant

A unisexual flower may be male or female. If male  and female flowers are present on the same plant  then the plant is Monoecious if male and female plants are present on a different plant than the plant is said to be Dioecious. Castor, Maize cucurbits are monoecious plants whereas Papaya Date palm are Dioecious.

Remember 👌🏽👌🏽A plant that has more than two types of flower like bisexual or unisexual such plants are called Polygamous like Mango.

Isomery in Flower Isomery is a condition in which a flower has the same basic number of parts in different floral organs. A flower is bimarous like Mustard whereas onion is an example of trimerous.A flower with different basic number of parts called heteromerous. Solanum nigrum is an example of hereromarous because it has five sepals, five petals, five stamen and two carpal.

Floral Phyllotaxy 

The arrangement of different floral organs on the thalamus is called floral phyllotaxy. When all floral organs are developed spirally, called spiral phyllotaxy in Magnolia. In Mustard Onion

Cyclic phyllotaxy is seen because floral organs are borne in a whorl. An intermediate condition  found in Ranunculus in which some floral organs are borne spirally and some borne in whorl, called Spirocyclic.

Floral symmetry

The arrangement of different floral organs around the axis of the flower. The axis of the stem on which the flower is developed is called the mother axis. If a flower is divided into two equal vertical halves by any vertical plane passing through the center then the flower is radial symmetrical or Actinomorphic like Mustard, Datura, Solanum.

If a flower is divided into two equal vertical halves by only a single  vertical plane passing through the center then the flower is  bilateral symmetrical or Zygomorphic like Pea Bean Cassia . A flower is asymmetrical if it can not be divided into two equal halves like Canna Opuntia.

Regular and irregular flower

If a flower is said to regular if there is no difference in shape size color and origin in member of each type of floral organ like Mustard If a flower is said to irregular if there is any difference in shape size color and origin in member of each type of floral organ.