Nerium is the genus for the plant species Nerium oleander. It is a member of the Apocynaceae or dogbane family and is currently the only species classified in the Nerium genus. Nerium oleander is sometimes known as exile tree, rose laurel, or Huang Hua Jia. The most recognized name for this plant, however, is oleander.
An evergreen shrub that can grow as a small tree when trained, oleander grows from 3 to 20 feet (91.44 to 609.6 cm) in length and has a 3- to 12-foot (91.44 to 365.76 cm) spread. It has dark green, glossy leaves and produces single- to double-bloomed flowers in spring and throughout the summer. Blooms grow in clusters and come in shades of yellow, pink, white or red.
A native plant to northern Africa, the Mediterranean and Southeast Asia, oleander prefers a dry, warm climate, but does well in warm, humid areas as well. It is quite popular in the US state of Florida and along parts of the Gulf of Mexico coast. Oleander is recommended for U.S. Department of Agriculture (USDA) hardiness zones 8 to 10. It is considered a hardy plant and will generally survive in temperatures as low as 15 to 20 degrees Fahrenheit (-9.4 to -6.7 Celsius). These cooler temperatures, however, may cause damage to the plant's foliage.
Oleander prefers full sun to partial shade. It can tolerate wet or dry soil as long as it has good drainage. Plants are considered drought-tolerant, but do better with supplemental watering during the hottest parts of the summer.
Useful as a border or privacy hedge, the oleander plant can also be used as a small-sized tree. To train, individuals should prune suckers back until only a few of the strongest stems remain. It can also be a suitable plant for a container garden.
Although used in many different landscape situations, all parts of the oleander plant contain the glycoside oleandrin, which makes the plant one of the most poisonous in the world. All parts of the plant are toxic. It should not be used where children play or in places where it may be ingested by pets.
Symptoms of oleander poisoning may include nausea, vomiting and severe abdominal pain. There may also be an increased heart rate, or the heart may even slow down. In some cases, victims may report a yellow halo effect in their vision. Severe poisoning can lead to cardiac arrest, and individuals should seek immediate emergency care if ingestion occurs.