Hydrophytes

Hydrophytes (water + plant) are plants which are able to live either in water itself or in very moist soils.

Hydrophytes share several survival characteristics:

1. A thin cuticle.
2. Stomata that are open most of time (as water is abundant).
3. An increased number of stomata.
4. A less rigid structure (water pressure supports them).
5. Large flat leaves on surface plants for flotation.
6. Air sacs for flotation.
7. Smaller roots (H₂O can diffuse directly into leaves).
8. Feathery roots (to support the plant).
9. Specialized roots designed to take in oxygen.

This buttercup is floating slightly submerged in water. Only the flowers are above the water. The leaves and roots are long and thin and almost hair-like; this helps spread the mass of the plant over a wide area, making it more buoyant. The long roots and thin leaves also provide a greater surface area for uptake of mineral solutes and oxygen.

The wide flat leaves of the water lily help distribute the plant's weight over a large area, thus helping it float near the water surface.