Water Lilies

Species of water lilies are prominent in many shallow-water habitats, from the boreal zones to the tropics. The genera are described below, with particular reference to species occurring in North America.

There are about 40 species of water lily (Nymphaea spp.). The white water lilies (Nymphaea odorata and Nymphaea tuberosa) are widespread in North America, and have large, roundish leaves with a triangular cleft at one end, at the point of which the petiole attaches. The large flowers are colored white, or rarely pink. The blue water lily (Nymphaea elegans) occurs in the southern United States and down south into Latin America, and has bluish or pale violet flowers.

The are about 10 species of yellow water lilies or spatterdock (Nuphar spp.), including the widely dispersed North American species Nuphar microphyllum, N. variegatum, and N. advena. The floating leaves of these plants are rather oblong in shape, with a basal cleft, at the apex of which the petiole attaches. The flowers are greenish on the outside, and are bright-yellow or sometimes reddish on the inside.

The water-shield (Brasenia schreberi) occurs widely in ponds and shallow waters along lake and pond shores in North America, Central and northern South America, and Eurasia. The petiole joins the oblong, floating leaves at their center, a morphology known as peltate. The flowers are relatively small, and are colored a dull red.

There are about seven species of fanwort or water-shield, including Cabomba caroliniana, a widespread species of pools and quiet streams over much of North America. This species has dense, oppositely arranged, finely dissected, submersed foliage, as well as small, alternately arranged, floating leaves. The six-petalled flowers are relatively small, and are colored white or lavender.

The lotus lily or water chinquapin (Nelumbo lutea) occurs in scattered populations in North America. The roundish leaves float on the water surface, or are held slightly above, and the petiole is attached at the middle. The flowers are pale-yellow in color. The Oriental sacred lotus (N. nucifera) and sacred lotus (N. nelumbo) are native species in Asia, and are widely cultivated ornamentals there, and sometimes in North America and Europe.

The largest-leafed species in the Nymphaeaceae is the royal water lily (Victoria amazonica) of tropical South America, whose floating leaves can be larger than one-meter across, and can support the weight of a child.