Question

Axile placentation occurs in
(a) Asteraceae and Fabaceae
(b) Brassicaceae and Solanaceae
(c) Solanaceae and Liliaceae
(d) None of the above

Answer 1

Hint: Axile placentation is found in a large family, commonly called a potato family. It shows the presence of a swollen placenta. They play an important role in the production of medicines and herbs. It is a common characteristic representative of the monocotyledonous family.

Complete answer:
Placentation refers to the arrangement of ovules within the ovary. Ovules are attached to ovarian walls through the placenta. Axile placentation is commonly seen in Solanaceae, Rutaceae, Liliaceae. In bicarpellary to multicarpellary the axile placentation is present, syncarpous ovary, the carpels fuse to make septa forming a central axis and ovules are arranged on the axis.
-Basal: The placenta is found in mono to multicarpellary, syncarpous ovary. Usually, at the base, a single ovule is attached. E.g.: Helianthus.
-Parietal: It is found in the bicarpellary to multicarpellary syncarpous ovary. The unilocular ovary becomes bilocular due to the formation of the false septum. E.g.: Cucumber.
-Free central: It is found in the bicarpellary to multicarpellary syncarpous ovary. Ovules are found on the central axis in unilocular condition after the false septum degrades. E.g.: Dianthus, Primula (primroses)
-Marginal: This type of placentation is found in the monocarpellary unilocular ovary, the placenta forms a rigid along ventral side, and ovules are arranged in two vertical rows. E.g.: Pisum sativum (pea).
-In axile placentation, the carpels are folded inward with ovules placed along the central axis of the ovary. e.g., tomato, lemon.
-It is found in the bicarpellary to multicarpellary syncarpous ovary.
-The placenta is axial and the ovules are formed at the angles where the septa join the central placenta.

So, the correct answer is “Solanaceae and Liliaceae”.

Note:
In axile placentation, the carpels are folded inward with ovules placed along the central axis of the ovary. e.g., tomato, lemon. It is found in the bicarpellary to multicarpellary syncarpous ovary. The placenta is axial and the ovules are formed at the angles where the septa join the central placenta.