Do Water Lily Plant Leaves Have Waxy Undersides?
- A water lily's flat leaves have a glossy, waxy, water-repellent upper-side. The waxy covering is known as the "cuticle." The underside is not waxy. It is buoyed up by the water's surface and sometimes has purple pigments, which assist in maximizing photosynthesis in the plant. Green pigment-containing chloroplasts required for photosynthesis are found only on the upper surface of the leaves, the only part of the leaf receiving sunlight. According to the Offwell Woodland and Wildlife Trust, stomata, microscopic pores in plant leaves through which gases are exchanged, are also found only on a leaf's upper surface. The thick, waxy cuticle repels water, which keeps the stomata open and clear and able to perform photosynthesis effectively.
- Water lily leaves are broad, generally 6 to 8 inches in diameter, circular and notched from the leaf's edge to its center. They remain flat on the water to optimize access to sunlight. They have a spongy interior, in what is called the mesophyll layer, with well-developed air chambers that give the leaf buoyancy. They also have hard, thick-walled cells, called sclereids, within the mesophyll that provide some hardness for the leaf, protecting its layers from damage. A water lily leaf can be folded over and flattened by waves and wind without being damaged.
- The Offwell Woodland and Wildlife Trust compares water lilies to trees. It notes that trees developed a lot of structure, such as bark and vascular tissue, to grow taller than all other plants to receive most of the available sunlight. Water lilies do the same thing, but with the minimum of structure. Their leaves form a canopy of leaves which dominates their aquatic environment, just as trees dominate in a forest, the trust says. Water lily leaves can cover the water's surface to a point where they limit the amount of light reaching the water's depths. This holds back algae growth, which allows other aquatic life to thrive. Texas A&M University AgriLife Extension Service recommends planting enough water lilies in a pond to cover 50 to 75 percent of the surface area or approximately one for every 10 square feet of surface area to hold back algae growth.
- Water lilies come in two types, tropical and hardy. Tropical water lilies are available with leaves in colored patterns of deep red or brown. Some tropical water lilies varieties are also viviparous and have the ability to produce small plants, or plantlets, along the surface or edge of their leaves. The first sign of a plantlet is the development of a nub at the point at which the leaf and stem join.