Question

Which flower has only either pistil or stamen?

Answer 1

Hint: Unisexual flowers has only either pistol or stamen as the reproductive structure and therefore they are referred as incomplete flower. example of such flowers are cucumber, papaya etc

Complete answer:
A flower is the reproductive organ of the plant body and a flower consists of Petals, sepals, stamens and carpels.
A flower having both the pistil and stamen are considered as bisexual flowers but flowers that have either pistil or stamen are known as unisexual flowers.
Pistils are the female reproductive structure of flower consisting of stigma , style & ovary; which carries the female egg cell and stamens are male reproductive structure consisting of filament & anther which further carries the pollen grain. Pollen grains are the male gamete.
The flowers which carry only pistils and lack stamen are called pistillates.
The flowers which carry stamens and lack pistil are called staminate.
Imperfect flowers are either the pistillate or the staminate. Hence their name is imperfect as they bear only one kind of reproductive structure in their flower. Other name for being pistillate is carpellate, having only functional carpels in them.

Therefore the correct answer is ‘Unisexual flower’.

Note:
Flowers which bear either only pistil or stamen are called unisexual flowers. Also related term to unisexual flowers can be the ‘imperfect flower’ which indicate that flower like either stamen or pistil or having only one of them.
Stamen is the male organ consisting of anther and filament.Pistil or carpel is the female reproductive organ consisting of Style, Sigma and ovary.