Question

Distinguish between the following:
Polysepalous and gamosepalous calyx.

Answer 1

Hint: Calyx is the sterile outermost whorl of the flower which constitutes perianth. It is formed by a group of sepals which are either separated or fused. The number of calyx varies between different plant species. The sepals are leafy and usually green in colour. Few flowers also consist of coloured sepals. The calyx can be divided into two- polysepalous and gamosepalous calyx.

Complete answer:
The major difference between polysepalous and gamosepalous calyx is the structure of sepals. The flowers in which the sepals are fused either wholly or at the base only are called gamosepalous flowers. Some of the examples of gamosepalous flowers are Hibiscus and periwinkle.
The flowers in which the sepals or calyx lobes are free i.e., the sepals are not fused are called polysepalous flowers. Examples include rose, southern Magnolia, cassia etc.

Additional information:
The calyx is the first part of a flower to develop and it is attached directly to the stem of the plant. Inside the calyx, petals are formed along with the other parts of the flower. The calyx has an important function which is to harbour the flower from its budding stage to the flowering stage against harsh environmental conditions such as desiccation, strong winds etc. Sometimes the calyx is modified to perform special tasks.

Note:
Calyx can also be differentiated based on its size, structure, colour and persistence of calyx. Based on size, calyx can be regular or irregular. Based on the structure calyx can be classified as tubular (tube like sepals), infundibuliform (funnel shape calyx), urceolate (urn shaped calyx), bilabiate (calyx having two lips), campanulate (bell shaped calyx) and cupulate (cup like calyx). Based on colour it can be classified as either sepaloid (green sepals) or petaloid (colourful sepals).