Question

Capitulum inflorescence is found in
(a) Compositae (Asteraceae)
(b) Cruciferae (Brassicaceae)
(c) Solanaceae
(d) Malvaceae

Answer 1

Hint: Capitulum inflorescence is found in a family which is believed to be a very large and widespread family of flowering plants rivalled only by Orchidaceae. Almost all the members of this family bear flowers in dense heads surrounded by involucral bracts.

Complete Answer:
Capitulum inflorescence is found in Compositae also known as Asteraceae. Let's begin the explanation by understanding what an inflorescence is. A modified shoot where the shoot apical meristem transforms into floral meristem is termed as a ‘flower.’ During this transformation, the internodes do not elongate, instead the axis gets condensed. Thus, ‘inflorescence’ is the term used to define the arrangement of flowers on the floral axis.

Now let's see the classification of inflorescence in brief.
There are five major types of inflorescence. They are solitary flowers, racemose inflorescence, cymose inflorescence, mixed inflorescence and special inflorescence. The racemose inflorescence is an intermediate type of inflorescence where the arrangement of flowers is either acropetal or centripetal.

It is further of two types: simple and compound.
The simple racemose inflorescence is an indefinite inflorescence in which the peduncle is unbranched. It includes the following subtypes: typical raceme, corymb, corymbose raceme, umbel, spike, spikelets, catkin (amentum), spadix and capitulum (racemose head).

Let's further study about capitulum inflorescence.
Capitulum inflorescence is also known as ‘Head inflorescence.’ In this type a short dense spike is present over which the flowers are borne directly on a broad, flat peduncle, giving the inflorescence the appearance of a single flower. Examples are flowers of the family Asteraceae such as common daisy, sunflower, dandelion etc.

So, the correct answer is 'Compositae (Asteraceae)'

Note:

- Capitulum is also known as ‘pseudanthium’.

- Members of the family Cruciferae (Brassicaceae) often show compound corymb inflorescence.

- Solanum nigrum of the family Solanaceae shows scorpioid (cincinnus) inflorescence. It is a type of cymose inflorescence.

- Inflorescence structure in Malvaceae is called a bicolour unit. A Bicolor unit consists of determinate cymose structures.