Hello, The most well-known trees that have pneumatophores for respiration are mangrove trees.

What are Pneumatophores?

• Pneumatophores are special aerial roots that grow vertically upwards, out of the muddy, waterlogged soil they live in. They have tiny pores (lenticels) that allow them to take in oxygen directly from the atmosphere.

Why are they needed?

• Mangroves grow in coastal swamps and tidal flats where the soil is thick, muddy, and very poor in oxygen (anaerobic). The regular underground roots cannot get enough oxygen to survive. Therefore, the tree sends these "breathing roots" or "snorkels" up into the air to respire.

A prime example, especially relevant to your location in Kolkata, is the Sundari tree (Heritiera fomes), after which the Sundarbans mangrove forest is named. Other common examples include species of Avicennia and Sonneratia.

Hope it's helpful to you.