Corolla:

It is second floral whorl present inner to calyx and composed of petals. The petals are usually brightly coloured due to the presence of pigments fond in chromoplasts of cells. Some time the petals may be green in colour called sepaloid. If the petals are free from one another in the corolla, the condition is polypetalous or choripetalous and if there is any degree of fusion between the petals, the corolla is said to be gamopetalous or sympetalous.

       Like of the calyx the corolla is caduceus (grapevine) mostly deciduous and very rarely it is persistent (Heather).

1. Forms of corolla

Types of polypetalous corolla are:

1. Cruciform: Presence of four, free, unguiculate petals arranged in form of a cross e.g. Brassica ( Sarson).
2. Caryophyllaceous: There are five unguiculate petals. The limbs of petals spread outward and lie at right angle of claw e.g. Dianthus (Pink).
3. Rosaceous. The petals are five or more than five having very reduced or sessile claw.
4. Papilionaceous: It is butterfly-shaped irregular corolla consist of five petals. The posterior petal is largest known Standard of Vexillum. Two lateral petals are small and free called Wings and are overlapped by the posterior  standard petal. The two anterior petals are fused to from innermost boat-shaped structure covering the stamens and carpel of the flower and is spoken as Keel or Carina. It is overlapped by wings or alae e.g. members of family Papilionaceae e.g. Pea.

Functions of corolla

2. Functions of corolla

1. Corolla attracts insects for pollination when they are beautiful and coloured or forms nectar pockets on the petals or collect nectar at its base.
2. Sometime scented ducts are present on the petals which also help in attracting insects. These ducts produce scent which is used in the preparation of various perfumes.