Question

Which of these is an example for a zygomorphic flower with imbricate aestivation?
A. Canna
B. Cassia
C. Cucumber
D. Calotropis
E. Mustard

Answer 1

Hint: A zygomorphic flower is a type of flower that can be divided into two halves only when a line passes from the middle of the flower. In imbricate aestivation, one petal of the flower is internal, one is external and in the remaining petals, one margin is internal and one is external. The flower that is zygomorphic and shows imbricate aestivation is yellow in colour and known as the Indian Laburnum.

Complete answer:
Cassia is an example of a zygomorphic flower with imbricate aestivation.
Cassia is a flowering plant that is native to India and its adjacent countries. The plant is used for its medicinal purposes and the flowers are also consumed by some people.

Additional information:
Let us have a look at the other types of flowers based on their floral symmetry:
> Actinomorphic: a flower that shows radial symmetry. For example, Hibiscus
> Asymmetric: a flower that cannot be divided into 2 equal halves. For example, Canna.
Other than imbricate, the other types of aestivation are:
> Valvate: when the petals or sepals just touch the margin of each other.
> Twisted: when one margin of the sepal or petal overlaps with the next one.
> Vexillary: out of the 5 petals when one large standard petal overlaps the two lateral petals, which in turn overlap the smallest anterior petals.
> Quincuncial: when the arrangement is such that two petals are completely inside the whorl, two are completely outside and one margin of the last petal is inside and one is outside.

The correct answer is option ( B ) that is Cassia.

Note:
> The cassia is even referred to as the ‘golden shower’.
> The seeds produced by this flower remain viable for as long as a year.
> Even though it has various uses, it is predominantly used as an ornamental tree.