Question

Out of 5 petals of a flower bud, the standard petal overlaps the two wing petals which in turn overlaps two smaller keel petals. This type of aestivation is called:

• A. Twisted
• B. Valvate
• C. Vexillary
• D. Imbricate

Answer 1

The correct option is C Vexillary

The mode of arrangement of sepals and petals in the flower is called aestivation.

If the largest petal (standard) overlaps the two lateral petals (wings) which in turn overlaps two smaller anterior petals (keel), then the aestivation is known as vexillary or papilionaceous. Example: Pea and bean flower.

Vexillary

In valvate aestivation, margins of the sepals or petals touch each other without overlapping as in mustard and Calotropis.

Valvate

If the margins of sepals or petals overlap one another but not in any particular direction, then the aestivation is called imbricate. Example: Cassia and gulmohur.

Imbricate

If one margin of sepal or petal overlaps that of the next one, then the aestivation is called twisted. Example: China rose, lady’s finger, cotton.

Twisted