Question

Five groups of extremely reduced male flowers, each group consisting of a single anther on a stem is found in which inflorescence?
(a)Cyathium
(b)Dichasial cyme
(c)Panicle
(d)Verticillaster

Answer 1

Hint: The inflorescence bearing such flowers is one of the specialized pseudanthium forming or “false flowers” forming inflorescence seen in the genus Euphorbia. This kind of inflorescence also has five bracteoles and one extremely reduced female flower.

Complete answer:
Cyathium inflorescence is an inflorescence with unisexual, apetalous male and female flowers.
A cyathium inflorescence consists of:
- Five sometimes four bracteoles which are small, united bracts forming a cup-like involucre. Their tips are free and they cover the opening of the involucre.
- These bracteoles alternate with five nectar glands, which may be present singly or may be fused.
- One extremely reduced female flower in the center and consists of an ovary on a short stem with a pistil.
- These female flowers are surrounded by five groups of extremely reduced male flowers (one group at the base of each bracteole), each consisting of a single anther present on a stem.
So, the correct answer is, “Cyathium”

Note: - Though cyathia are said to be one of the types of inflorescence producing false flowers, the flower-like characteristics are underlined by brightly colored nectar glands and often also through the petal-like appendages to the nectar glands.
- Sometimes the cyathia may be present solitarily but is usually present as a second-order inflorescence in cymes, pseudumbels, etc.
- Most cyathia have cyathophyllum surrounding them that are upright and provide protection but rendering the nectar glands inaccessible.