Question

Which of the following describes imbricate aestivation?

• A. Appendages in a whorl just touch one another at the margin, without overlapping
• B. If one margin of the appendage overlaps that of the next one and so on
• C. If the margins of appenages overlap one another but not in any particular direction
• D. The largest appendage overlaps the two lateral petals appenadages which in turn overlap the two smallest anterior appendages

Answer 1

The correct option is C If the margins of appenages overlap one another but not in any particular direction

The mode of arrangement of floral appendages (sepals and petals) in floral bud with respect to the other members of the same whorl is known as "aestivation".

There are a few types of aestivation

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

Valvate: When sepals or petals in a whorl just touch one another at the margin, without overlapping, as in Calotropis, it is said to be valvate.

Twisted: If one margin of the appendage overlaps that of the next one and so on as in cotton, it is called twisted.

Vexillary: In pea and bean flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary.