Assertion: Corolla of Cassia shows imbricate aestivation.
Reason: In the corolla, the posterior odd petal overlaps the two lateral petals known as wings or alae which in return overlap the anterior two fused petals and the overlapping is from posterior to anterior in descending manner.
In valvate aestivation, the sepals or petals of a whorl touch one another at the margins but not overlapped. ex: calyx and corolla of Calotropis, calyx of pea and bean, calyx and corolla of makoi.