Nymphaea is a plant genus that is part of the Nymphaeaceae family. It contains about 40 species of flowering plants that are found in North America, Africa, Europe, and Asia. They grow in aquatic environments and usually consist of a floating flower and floating leaves. Most of the species are classified as perennial and deciduous. Although relatively easy to maintain, the plants in this genus are susceptible to damage from pests and diseases.
The genus name is derived from the word "nymph," which aptly describes the delicate nature of the plants. Commonly, these plants are known as a type of water lily. Many of the species have variations on the common name. For example, Nymphaea odorata is referred to as the American white water lily, and Nymphaea mexicana is called the yellow lily.
This genus of plants is distributed throughout the world. Nymphaea caerulea is native to eastern Africa and India, while Nymphaea alba is found in Europe. Nymphaea odorata comes from the United States and Canada.
Most species in this genus are grown in water. Water gardens are the ideal venue to grow Nymphaea plants, but a pond is also a great place to plant a water lily. The aquatic environment should be shallow and have calm waters. Rushing water will prevent the water lily from establishing itself in a particular location.
Generally, the water lily is placed in a basket that is filled with loam and a layer of pea-shingle. The basket is usually sunk 10 inches (25 cm) below the surface of the water. As the water lily grows, the basket is lowered to about 20 inches (50 cm) below the surface.
Nymphaea alba has a spread of about 3 feet (1 m) and grows about 4 inches (10 cm) in height. It features large rounded leaves that are initially light brown in color, but quickly turn green. The fragrant flower is star shaped, consists of white petals, and has a yellow center.
Since water lilies live in a wet, humid environment, they are prone to fungal infections. Leaf spot is a common fungal disease that affects the leaves of the water lily. Reddish spots appear on the leaves and stems followed by yellowing of the leaf. Usually, separating affected plants from the rest of the garden will prevent further infections. Applying a fungicide to the water lily will help eliminate the fungus.