(c)Aestivation The mode of arrangement of sepals
or petals in floral buds with respect to other members of the same whorl is
known as aestivationMain types of aestivation are(i) Valvate When sepals or
petals in a whorl just touch one another at margin without overlapping  ., Calotropis(ii) Twisted If one margin of
the appendages ovarlaps that of the next one and so on. ., China rose, cotton, ladys finger(ii) Imbricate If the margins
of sepals or petals overlap one another but not in any particular direction, ., Cassia and gulmohar(iv) 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 or papilionaceous |