The large, flat leaves known widely as “lily pads” belong to a diverse group of aquatic plants that anchor themselves to the muddy bottom of slow-moving waters. These iconic floating structures are the foliage of two main plant genera, the Water Lily (Nymphaea) and the Lotus (Nelumbo), which produce the flowers often associated with them.
The Relationship Between the Pad and the Flower
The common phrase “flowers that grow on lily pads” implies a direct physical connection that does not actually exist in the botanical structure of these plants. The pads are the leaves, and the flowers are separate reproductive organs, each supported by its own stalk rising from the aquatic substrate. These plants are anchored by a thick, fleshy stem called a rhizome, which is buried in the mud at the bottom of the pond or lake.
Both the leaf (pad) and the flower emerge independently from the submerged rhizome. The leaves are supported by a long, flexible stalk called a petiole, while the flower is supported by its own stalk, the pedicel. These stalks travel up through the water column, often containing specialized air channels (aerenchyma) that transport oxygen from the surface down to the submerged root system. The flower is never attached to or structurally supported by the leaf itself.
Water Lilies (Nymphaea)
The most common plant associated with the term “lily pad” is the water lily, belonging to the genus Nymphaea. Water lily pads are typically circular and characterized by a distinctive, V-shaped slit or sinus that extends from the edge toward the center where the petiole attaches. These leaves are waxy, helping them repel water and float directly on the surface of the water.
The flowers of Nymphaea species are renowned for their delicate, cup-shaped structure and come in a wide range of colors, including white, pink, red, and yellow. Hardy water lilies generally produce flowers that float right on the water surface or rise only a few inches above it. Tropical varieties, however, often hold their blooms more distinctly above the water.
Water lily flowers exhibit a fascinating daily cycle, with many species opening in the morning and closing again in the late afternoon for three to four days. During the first day of blooming, the female reproductive parts, or pistils, are receptive to pollen, often filling the center of the bloom with a sugary fluid to attract insect pollinators. On the subsequent days, the male stamens mature and release pollen, ensuring cross-pollination with other flowers.
The Distinctive Lotus (Nelumbo)
The other major genus whose leaves are frequently mistaken for water lily pads is the lotus, Nelumbo, which contains the American lotus (N. lutea) and the sacred lotus (N. nucifera). A primary distinction is that the lotus leaf is completely circular with no slit, and the petiole attaches directly to the center of the pad. Unlike water lilies, the lotus pads are generally held high above the water surface on stiff stalks, sometimes reaching up to two feet in height.
The leaves of the lotus are also famed for their extreme water-repellent property, known as the “lotus effect.” This is due to a microscopic surface structure of tiny bumps, or papillae, covered in a waxy coating that makes the surface ultrahydrophobic. When water lands on the leaf, it beads up into spheres and rolls off, collecting dirt particles in the process, which is why the leaves remain remarkably clean even in muddy environments.
Lotus flowers are typically larger than those of the water lily and are also held high above the foliage on strong, rigid stalks. These showy, fragrant blooms are followed by a distinctive, cone-shaped seed head that resembles a shower head, which is a key visual identifier.