Types of Aestivation

Aestivation can be classified into four main types:

• Valvate: Sepals or petals are arranged without overlapping edges, just touching each other.
• Twisted: One margin of each sepal or petal overlaps the next one, forming a twisted appearance.
• Imbricate: Margins of sepals or petals overlap irregularly, not in any specific pattern.
• Vexillary: A special type in pea family where the largest petal (standard) overlaps the two lateral petals (wings), which in turn overlap the smallest petals (keel).

By observing the arrangement of sepals and petals in a bud, one can distinguish between these types.