The mode of arrangement of sepals or petals in a floral bud is known as aestivation . Draw the various types of aestivation possible for a typical pentamerous flower.

Explanation

The mode of arrangement of sepals or petals in a flower bud with respect to the members of the same whorl or with each other is known as aestivation . It is of following types
Valvate Margin of adjacent petals or sepals touch each other , but do not overlap, e.g., mustard (Brassica).
Twisted Regular overlapping of petals or sepals occurs in which margin of one petal overlap with the adjacent next one petal, e.g. , China rose (Hibiscus rosa sinensis) .
Imbricate There are five petals arranged in such a way that one petal is completely external and one petal is completely internal, three petals are partially external and partially internal, e.g., Cassia, Callistemon, Caesalpinia.
Quincunical There are five sepals or petals of which two are completely out and two are completely inside, while one is partially out and partially in e.g., Cucurbita (Cucurbitaceae) .
Vexillary It is the charcteristic aestivation of corolla of family -Papilionaceae, in which corolla (petals) are papilionaceous.
The largest petal overlap the two lateral petals (wings) , which in turn overlap the two smallest anterior petals (Keel) e.g., Artobotrys , Polyalthea, Pisum.