Question

Describe in brief the various types of placentation found in flowering plants.

Answer 1

Hint: Placentation is the mode of distribution of placenta inside the ovary. Placenta is a tissue that connects ovules and ovary. Ovules are present in the ovary in the angiosperms.

Complete step by step answer:
The types of placentation in flowering plants:
1. Axile Placentation: It is a type of placentation that can be seen in bi- or multi carpellary, syncarpous ovary. The walls of the carpel meet in the centre of the ovary, where the placenta are formed like a central column. The ovules are borne at or near the centre on the placenta in each locule. Example: Hibiscus.
2. Marginal Placentation: This placentation takes place in a monocarpellary, unilocular ovary. The ovules are borne along with the junction of the two margins of the carpel. Example: Fabaceae
3. Parietal Placentation: This type of placentation occurs in multi carpellary, syncarpous, unilocular ovaries. The carpels are only fused by their margins. The placenta that bear ovules develops at the places, where the two carpels are fused. Example: Cucumber
4. Basal Placentation: This type of placentation can be seen in bicarpellary syncarpous and in unilocular ovary. The placenta develops directly on the receptacle that bears a single ovule at the base of the ovary. Example: Asteraceae.
5. Superficial Placentation: This type of placentation takes place in a multicarpellary, multilocular ovary. The ovules are borne on placentae, that develops all round the inner surface of the partition wall. Example: Nymphaeaceae

Note:
There are five types of placentation that occurs in flowering plants i.e. axile, marginal, parietal, basal, superficial placentation. Placentation is the method of distributing placenta inside the ovary.
The function of placentation ihelps in the transfer of nutrients, respiratory gases, and water from maternal tissue to a growing embryo, and in some instances to remove waste from the embryo.