Question

The inflorescence of Brassica campestris is?
A. Raceme
B. Corymb
C. Corymbose raceme
D. Spadix

Answer 1

Hint: Brassica campestris belongs to the mustard family ( Brassicaceae) or (Cruciferae). The flowers are arranged in the plant in an acropetal fashion. The new flowers resemble corymb. But the older flowers are not that large to bring them to the top level.

Complete answer:
The inflorescence of Brassica campestris is corymbose raceme inflorescence.
The racemose inflorescence shows indefinite growth, and an active growing point is present. The arrangement of flowers is mostly 2 types. Acropetal, where older flowers are towards the base and younger ones are towards the apex or centripetal, where the older flowers are towards the periphery and the younger ones are towards the center.
All these options are different kinds of a racemose inflorescence. Let’s go through the basics of each.
Raceme – It is unbranched. The flowers are found typically with pedicels. And these pedicellate flowers are arranged in an acropetal fashion. Examples are Lupin, Radish, etc.
Corymb – This resembles raceme in that it is also unbranched, and pedicellate flowers are arranged acropetally. But in the pedicels of the lower (older) flowers are longer, and this brings all the flowers to the same level. Examples are Iberis, hawthorn, etc.
Corymbose raceme – As the name suggests, it is a kind of amalgamation of the 2 above-mentioned inflorescences. The younger flowers (top part) resemble corymb (the younger few flowers are at the same level because of elongated pedicels). But the pedicles of the older flowers (the lower part) are not that long to reach the same level, thus giving it an overall raceme look. Examples are Brassica campestris, Hydrocotyle, etc.
Spadix – It is a special type of spike racemose inflorescence. This has a peduncle, which holds the flowers. The appendix of the peduncle is colored to attract insects for pollination. The peduncle has unisexual flowers in its lower part, male flowers on the upper side, and female flowers on the lower side. Examples are Colocasia, Arum, etc.

Note:
Remember that Raceme is only a type of racemose inflorescence, and so are the other options. So it is important to read the question carefully and find out which racemose inflorescence is shown by the plant in question (Brassica campestris is the scientific name for mustard). In the mustard family, the flowers have four petals, four sepals, and six stamens. Silique is the fruit of the mustard family. Inflorescence of brassica campestris is the combination of receme and corymb.