Explain in detail androecium of an angiospermic flower.

Androecium (A): 

a. It is third floral whorl from outer side. 

b. Androecium is male reproductive part of a flower. 

c. The individual member is known as stamen. 

d. If all the stamens are free the condition is polyandrous and synandrous if they are fused. 

e. Typical stamen shows three different parts: 

1. Anther: It is terminal in position. Anther produces pollen grains. It is usually dithecous (two anther lobes), tetralocular/tetra sporangiate (four pollen sacs) structure, e.g. Datura. 

In some plants it is monothecous (single lobed), bilocular or bisporangiate structure e.g. Hibiscus. 

2. Filament: It is a stalk of stamen and bears anther at its tip. It raises anther to a proper height for easy dispersal of pollen grains.

3. Connective: It is in continuation with the filament. It is similar to mid rib and connects two anther lobes together and also with the filament. 

4. Gynoecium (G): 

a. It is the female reproductive part of a flower and innermost in position. 

b. It is also known as pistil. 

c. The individual member of gynoecium is known as carpel. 

d. The number of carpels may be one to many. 

e. If all the carpels are fused the condition is described as syncarpous and if they are free the condition is described as apocarpous. 

f. The polycarpellary gynoecium can be bicarpellary (two carpels e.g. Datura), tricarpellary (three carpels e.g. Cucurbita), pentacarpellery (five carpels e.g. Hibiscus) and so on. 

g. A typical carpel consists of three parts stigma, style and ovary.

1. Stigma is a terminal part of carpel which receives pollen grains during pollination. It helps in germination of pollen grain. Stigma shows variation in structure to suit the pollinating agent. 

2. Style is narrow thread like structure that connects ovary with stigma. 

3. Ovary is basal swollen fertile part of the carpel. Ovules are produced in ovary on a soft fertile tissue called placenta.