Question

What is vexillum?

Answer 1

Vexillum:

1. Aestivation (in botanical terms) is the arrangement of sepals and petals in floral buds with respect to other members of the whorl.
2. It is generally confused with vernation, which is known as the arrangement of scales and new leaves in a leaf bud before it opens.
3. The sepals and the petals are collectively known as a perianth.
4. Vexillum is used to refer to the standard, large posterior petals of papilionaceous flowers (corolla).
5. The posterior large bilobed petal of the papilionaceous corolla is called standard or vexillum.
6. They overlap the two smaller lateral petals known as alae or wings.
7. These are quite large, single, upper petals which are also referred to as the banner or the standard petal.