What is aerenchyma? Mention any two specific functions of this tissue

What is aerenchyma? Mention any two specific functions of this tissue in hydrophytes.

Aerenchyma is a modified parenchyma, where the cells are arranged with regular air spaces or air chambers to facilitate diffusion of gases to provide buoyancy to aquatic plants such as lotus and water hyacinth.

Two functions of hydrophytes are
(i) It helps in the diffusion of oxygen, both in and out.
(ii) It provides buoyancy to aquatic plants.