Question

In the family Papilionaceae, 5 petals form a unique association, in which 3 different elements participate; these are vexillum, alae, carina. What is the number of these elements?
(a)1, 2, 2 respectively
(b)2, 1, 2 respectively
(c)1, 1, 3 respectively
(d)2, 2, 1 respectively

Answer 1

Hint: This shows the arrangement of five different petals in the corolla of the papilionaceous flowers. These petals are designed in such a manner that it can attract the pollinators to pick the nectar easily from these flowers.

Complete answer:
In the Papilionaceae family, unique aestivation is formed in which three different elements participate in different numbers namely one vexillum, two alae, and two carinae. The corolla of papilionaceous flowers usually has five petals that include a large upper petal vexillum which is enclosing two lateral wings like petals named alae and a lower carina with two united petals.

Additional Information:
-The term Papilionaceae is taken from the Latin word 'papillon' which means ' a butterfly'.
-The name Papilionaceae is given to the family because of the flowers of this family is characterized by irregular and butterfly-like corolla in many plants such as bean, pea, etc.
-Vexillum is also known as standard and is the biggest, single, and posteriorly positioned petal.
-The base of the vexillum is semicylindrical in shape which embraces and compresses two lateral small wings like petals called alae.
-The carina is a pair of small keel petals that are enclosed by the wings of alae and are situated below the wings.
-The pair of keel petals are fused together at the base forming a boat-like structure.
-These petals in the corolla are designed in such a way that it will help in pollination, and hence it increases the chances of successful reproduction of the flowers.

So, the correct answer is, '1, 2, 2 respectively'.

Note:
-The name Papilionaceae is given to the family because the flowers of this family are characterized by irregular and butterfly-like corolla.
-Vexillum is the single, biggest, and posteriorly positioned petal.
-Alae is a pair that is winged like petals embraced and compressed by vexillum.
-Carina is also in pairs that are fused together and are enclosed by the wings of alae.