Question

Cyathium and hypanthodium inflorescence are related to having
A) Nectar glands
B) Unisexual flower
C) Both a and b
D) None of the above

Answer 1

Inflorescence can be defined as the arrangement of flowers on a floral axis. Cyathium and hypanthodium come under compound inflorescence.

Complete answer:
Let us analyse each given option to find out the correct option.

Option A: Cyathium contains a cup-shaped involucre provided with nectar-secreting glands. There are no nectar glands in hypanthodium. Therefore, this is an incorrect option.
Option B: Hypanthodium is a box-like inflorescence where the box is formed by the fleshy receptacle. It opens to the exterior by a single pore called the ostiole. The hollow pear-shaped fleshy receptacle encloses a number of minute male and female flowers, it becomes fleshy and forms the fruit. Cyathium is actually a flower cluster or inflorescence containing unisexual, apetalous male and female flowers. The similarity between the cyathium and hypanthodium inflorescence is the availability of unisexual flower. Therefore, this is the correct option.
Option C: Cyathium contains a cup-shaped involucre provided with nectar-secreting glands whereas there are no nectar glands in hypanthodium. However unisexual flowers are present in both. Therefore, this is an incorrect option.
Option D: The similarity between the cyathium and hypanthodium inflorescence is the availability of a unisexual flower. Therefore, this is an incorrect option.

Thus, the correct answer is option (D) Unisexual flower.

Note: It is to be noted that in cyathium, the female flower matures earlier. Female flowers are surrounded by small male flowers. The male flower, which lies toward the center, matures earlier than the flowers which are towards the periphery.