When the margins of sepals or petals overlap one another without any particular direction, the condition is termed as:
imbricate.
— Concept: This question tests your understanding of different types of aestivation, which refers to the arrangement of…Concept: This question tests your understanding of different types of aestivation, which refers to the arrangement of sepals or petals in a flower bud before it opens.
Why (C) is correct: In imbricate aestivation, the margins of sepals or petals overlap one another, but there is no specific direction or regular pattern to this overlapping. One petal/sepal may be entirely internal, and another entirely external, with the rest overlapping irregularly. Examples include Cassia and Gulmohar.
Why other options are wrong:
- (A) Valvate: Sepals or petals just touch each other at the margin without overlapping.
- (B) Vexillary: A specialized type of imbricate aestivation found in pea family (Fabaceae), where the largest petal (standard) overlaps two lateral petals (wings), which in turn overlap two smallest anterior petals (keel).
- (D) Twisted: One margin of the appendage overlaps the next one, and so on, in a regular direction (clockwise or anti-clockwise).
NEET Tip: Remember the examples for each type of aestivation as they are frequently asked. For imbricate, think 'Irregular Imbricate' (Cassia, Gulmohar).
Correct Answer: (C)
imbricate.