Flowers : defination, types, inflorescence, types of inflorescence | study science

 

  Flowers

 A flower is a reproductive part of a plant. Flower  is meant for sexual reproduction. Among different parts of plant, the flower is most colorful and attractive part. Flower are also a source of food for other living organisms. They are rich source of nectar.

A flower composed of 2 vegetative organ - calyx, corolla, and reproductive organ - androecium (stamen), gynoecium (carpel).

Types of flower

1. Flower on the basis of number of whorl can be categorized into unisexual and bisexual.

 

*Unisexual - when a flower consist of calyx, corolla and having either only stamen or only carpels is called unisexual flower.

* Bisexual - when a flower has both androecium and gynoecium along with calyx, corolla is called bisexual flower.

2. On the position of three whorls- calyx, corolla, and androecium with respect to the ovary, flower can be classified as hypogynous, perigynous or epigynous.

 

* Hypogynous -the gynoecium occupies the highest position. Other parts are situated below it. The ovary is said to be superior.

E.g. china rose, mustard

* Perigynous - the ovary is in the centre and all four whorls are almost at the same level. The ovary is said to be half inferior.

E.g. rose, plum

* Epigynous -  the other parts of flower arise above the ovary. The ovary is said to be inferior.

E.g. guava, cucumber

 

 

Inflorescence

The arrangement of flower on the floral axis is called inflorescence.

 

Types of inflorescence

Two major types of inflorescence are defined i.e racemose and cymose.On the basis of apex get converted into flower or continue to grow. 

1. Racemose inflorescence - The main axis keep growing and flowers develop in an acropetal pattern is called racemose inflorescence.

2. Cymose inflorescence - The main axis terminates in a flower, limited in growth. The flower follow the basipetal order.

                                Racemose inflorescence     Cymose inflorescence