Question

Among bitter gourd, mustard, brinjal, pumpkin, China rose, lupin, cucumber, sunn hemp, gram, guava, bean, chilli, plum, petunia, tomato, rose, withania, potato, onion, aloe, and tulip, how many plants have a hypogynous flower?
A) 18
B) 6
C) 10
D) 15

Answer 1

Floral whorls refer to the arrangement of the petals, sepals, leaves, stamens, and carpels. These positions are important in the floral formulae of the plant, and the classification of the flowers.

Complete Answer:
- Flowers can be categorised according to the relative positions of the gynoecium and the ovaries. In a hypogynous flower, the ovary is superior to the perianth and the stamens as these are attached to the receptacle below the ovary.
- Out of all the plants listed in the question. The flowers of mustard, brinjal, petunia, potato, tomato, China rose, lupin, sunn hemp, withania, onion, aloe, tulip, gram, bean, chilli, have hypogynous flowers. This is a total of 15, therefore option d is correct.
- As the total numbers given in options A, B, and C is not 15, these answers are incorrect.
- Of the remaining flowers, while those of rose and plum are perigynous flowers, pumpkin, bitter gourd, cucumber and guava are epigynous. When the position of the ovary is below or inferior to all the other parts of the flower, it is said to be epigynous.
- In perigynous flowers, the stamens, petals, and sepals fuse into a tube known as a hypanthium, and this attaches to the receptacle below the gynoecium, and then surrounds the ovary.

Hence the correct answer is option D.

Note: The gynoecium is divided into structures known as pistils. Each pistil consists of an ovary which is at the base, a stigma at the top or apical end which receives the pollen grains, and a long tube known as the style.