Pneumatophore is present in-

A) Rhizophora

B) Cholobranchia

C) Pistea

D) None of the above

Some plants that grow in swampy, marshy, or saline (salt water) areas develop special roots that grow vertically upwards above the ground. These roots are called pneumatophores.

• Normally, roots absorb dissolved oxygen from the soil. But in anaerobic soils (low in oxygen), gaseous exchange becomes difficult. In such conditions, pneumatophores help by directly absorbing oxygen from the air, allowing respiration to take place.
• Pneumatophores are also known as air roots. They enable plants to breathe in waterlogged or muddy habitats.
• These roots may grow upward from normal roots or sometimes arise from the stem. When they grow upward through the soil, many botanists call them aerating roots rather than aerial roots.
• The surface of pneumatophores has lenticels, which take in air into spongy tissues. Oxygen is then distributed throughout the plant using osmotic pathways.

Examples include Black mangrove and Grey mangrove, which can be identified by the presence of pneumatophores. However, plants like Pistia and Cholobranchia do not have pneumatophores, while they are found in Rhizophora.

Correct Answer: Option A