Question

Observe the following floral diagram and choose the correct option for calyx and androecium respectively.

• A. Imbricate aestivation and diadelphous androecium
• B. Imbricate aestivation and monadelphous androecium
• C. Valvate aestivation and diadelphous androecium
• D. Valvate aestivation and monadelphous androecium

Answer 1

The correct option is C Valvate aestivation and diadelphous androecium

Aestivation is the arrangement of the sepals and petals in their respective whorls.

Valvate aestivation is when the units are lying next to each other without their margins overlapping.

Imbricate aestivation is when there is irregular overlapping. There are usually 5 units (sepals or petals) one is completely out, one is completely in and the other three have their margins in and out. Here, the calyx (the outermost whorl of a flower and made up of units called sepals) is showing valvate aestivation and is gamosepalous (united).

Androecium shows 10 stamens arranged in 2 bundles of 9 + 1. The filaments of 9 stamens are fused and one is free. Hence, there are two bundles. This condition is called as diadelphous.

If all filaments are fused together to form one bundle, it is called a monadelphous condition.

Diadelphous condition