Final answer:
Aquatic plants use spongy gas-filled passages known as aerenchyma to aid in the diffusion of gases and provide buoyancy in waterlogged conditions.
Step-by-step explanation:
Aquatic plants are characterized by spongy gas-filled passages known as aerenchyma. Aerenchyma consists of large air spaces that provide buoyancy and aid in the diffusion of gases. In various aquatic plants including mangroves and wild rice, these structures are essential for survival under waterlogged conditions. In mangroves, pneumatophores, a type of specialized root, and in other aquatic plants such as wild rice, air spaces in the root cortex function as aerenchyma, highlighted in scanning electron microscopy images. Furthermore, beneath the epidermis of dicot leaves, the mesophyll contains spongy parenchyma which also assists in gaseous exchange and buoyancy.