What is aestivation? What are its different types and give examples?
Aestivation is the positional arrangement of sepals or petals in a floral bud. Different types of aestivations are: - (a) Valvate Aestivation: - Petals or sepals meet each other at the edge. They are arranged without overlapping. Example: - Guava and mustard. (b) Twisted Aestivation: - The overlapping of petals or sepals is done by one margin of each petal over the margin of adjacent petals. Example: - China Rose and cotton. (c). Imbricate Aestivation: -The margins of sepals and petals overlap. They do not overlap in a specific direction. Example: - Cassia and Gulmohar. (d). Quincuncial Aestivation: - The arrangement in which out of five parts of the flower, two petals or sepals are positioned internally, two petals or sepals are positioned externally, and the fifth part is situated externally at the margin. Example: - Guava. (e).Vexillary Aestivation: - There are five petals. The largest petal overlaps the 2 lateral petals which successively overlap the 2 smallest anterior petals. Example: - Bean and pea.
