Why do submerged plants not have stomata?

Submerged plants lack stomata primarily to adapt to underwater environments, reducing water evaporation and optimizing gas exchange. The leaves of submerged plants do not have stomata because their aerenchyma is particularly well-developed, a structure conducive to gas exchange in water. The leaves of submerged plants typically develop into very thin strips, ovals, filaments, or feather-like shapes, which increase the surface area to volume ratio, allowing leaf cells to make greater contact with the water, thereby absorbing inorganic carbon from the water.

Submerged plants exchange gases through their aerenchyma, a tissue that stores oxygen produced by photosynthesis and releases it through intercellular spaces. Additionally, the roots of submerged plants have regressed, allowing all organs to absorb water and nutrients. This structural adaptation enables them to survive and reproduce in underwater environments.