Mangrove of marshy sunderbans is characterised by

Options

A. Pneumatophores and viviparity.
B. Floating roots
C. Oviparity
D. all of these

Answer

### Step-by-Step Solution:

1. **Understanding Mangroves**: Mangroves are specialized trees that grow in coastal intertidal zones, particularly in marshy areas where saltwater and freshwater mix. The Sundarbans is a famous mangrove ecosystem located in the delta region of the Padma, Meghna, and Brahmaputra river basins.

2. **Characteristics of Marshy Areas**: Marshy areas are characterized by waterlogged soils, which can be muddy and have a high salt concentration. These conditions make it challenging for most plants to survive, but mangroves have adapted to thrive in such environments.

3. **Presence of Pneumatophores**: One of the key adaptations of mangroves is the presence of specialized roots called pneumatophores. These roots grow vertically upwards from the mud and have small pores (lenticels) that facilitate gas exchange. This adaptation allows the mangroves to take in oxygen, which is crucial for their survival in anaerobic (low oxygen) muddy conditions.

4. **Salt Tolerance and Salt Excretion**: Mangroves are also known for their ability to tolerate high salinity. They can excrete excess salt through their leaves, which can sometimes be seen as white crusts on the surface of the leaves or pneumatophores.

5. **Viviparity**: Another significant characteristic of mangroves is viviparity. This means that the seeds of mangroves germinate while still attached to the parent tree. The seeds develop into seedlings before they drop into the water or soil, ensuring that they are better prepared for survival in the challenging conditions of the mangrove environment.

6. **Conclusion**: Therefore, the mangroves of the marshy Sundarbans are characterized by the presence of pneumatophores for gas exchange and the phenomenon of viviparity, where seeds germinate while still on the parent plant.