Question

Above ground cleistogamous flowers are formed late in the season in
A)Balsam
B)Viola
C)Oxalis
D)All of the above

Answer 1

Hint: Cleistogamy is the process of self pollination in plants. They use the non opening self pollinating flowers. These flowers are seen in the peanuts, pansy and many plants of the grass family. In these plants the pollen is shed just before the flowers open.

Complete answer:
To solve this question, we must know about the process of cleistogamy and their examples.

The flowers which do not open so that they can self pollinate is called cleistogamy. These flowers are bisexual and the anther and the stigma is present close to each other so as to facilitate pollination. For example viola. These plants have two types of flowers. The flowers that are present on the upper branches are pollinated by insects blossom in early season whereas the one blossom near the ground bloom in the late season.

Balsam- the flowers of Balsam are protandric which means the male parts are reduced to the female. The stamens are fused to form a cover over the ovary and the male phase falls off. Thus the stigma becomes receptive. This reduces the chances of self pollination.

Oxalis- The leaves and flowers of this plant closes at night. They show photonastic movement.

Hence, the correct answer is option (B)

Note: Pollination is the process of transfer of pollen grains from the anther to stigma of the female flower. It takes place by self pollination as in bisexual flowers or by cross pollination is mediated by agents like insects, winds, water, animal etc.