Nerium oleander (oleander)
Nerium oleander, commonly known as oleander, is a highly toxic plant that has been cultivated since ancient times.
About this Species
Nerium oleander is a highly toxic ornamental shrub widely cultivated in the Mediterranean. It has been grown since ancient times and features in many of the Roman wall paintings in Pompeii.
Alexander the Great in his military campaigns is said to have lost men as a result of eating meat skewered on the highly poisonous Nerium twigs.
Geography & Distribution
Native to the Mediterranean region, Iran, the Indian subcontinent and southern China.
The oleander by Marianne North (Image: RBG Kew)
Nerium oleander is an evergreen shrub (or small tree) that grows to approximately 6 m. A sticky latex is exuded if the stem is cut. Leaves are usually in groups of three and narrowly lanceolate. The flowers are tubular with five lobes, red or pink in the wild, but in addition may be white, cream, yellow or purple in cultivars, and double forms have also been selected. Some are scented. The fruit is composed of a pair of follicles that split along one side to release the seeds. The seeds are oblong, with a plume of hairs at one end.
Threats & Conservation
Oleander is not threatened globally. Plants are threatened in the wild in some areas through excessive development, but will persist in cultivation.
- Medicine for cardiac conditions, cancer and leprosy
Nerium oleander is widely cultivated as an ornamental shrub or as an informal hedge in warm-temperate and dry subtropical regions, and as a plant for the conservatory in cooler climates. It is highly poisonous to humans, pets, livestock and birds due to the presence of cardiac glycosides, mainly oleandrin. Ingestion causes nausea, vomiting, cardiac arrhythmias, hypotension (low blood pressure) and death. Its sap has been used as rat poison.
Oleandrin is used for treating cardiac conditions in patients who cannot tolerate digitalis. In traditional medicine, the leaves have been used for a variety of medicinal purposes, including the treatment of heart diseases, as a diuretic, antibacterial, and against snake-bite. The leaves also show insecticidal activity against sugarcane mite and citrus leafminer. The roots have been used externally in traditional medicine for treating cancer, ulcers and leprosy. In Western Sahara the ash from Nerium oleander is mixed with saltpetre to make gunpowder.
Millennium Seed Bank: Seed storage
Kew's Millennium Seed Bank partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Number of seed collections stored in the Millennium Seed Bank: 2
Seed storage behaviour: Orthodox (the seeds of this plant survive being dried without significantly reducing their viability, and are therefore amenable to long-term frozen storage such as at the MSB)
Germination testing: Successful
Composition values: Oil content 17.4-29.4%, Protein 30%
A tender plant, Nerium oleander can survive light frosts, but show signs of frost damage. It is a common landscape plant in tropical and subtropical climates and grows in a wide range of soils. It can withstand drought and salt spray, being widely used in coastal areas, and reacts well to full sun or partial shade. The species can be propagated by semi-ripened cuttings in summer or seeds. Hard pruning helps to maintain its shape.
Keep up to date with events and news from Kew
- newly discovered
- around the world
- of use
- ground breaking
- english garden
- garden plants
Plants & Fungi blogs from Kew
09 Dec 2013
Sarah Cody explains how gap analysis is helping our partners collect the seed of crop wild relatives (CWR) for a project called 'Adapting Agriculture to Climate Change', run jointly by Kew's Millennium Seed Bank and the Global Crop Diversity Trust.
28 Nov 2013
Orchids have the smallest seeds in the world and they produce millions of them, but why? Kew's seed morphologist Wolfgang Stuppy explains the clever survival plan that lies behind this seemingly wasteful strategy.
13 Nov 2013
Sarah Cody explores the valuable contribution that visiting researchers to the Millennium Seed Bank make to our understanding of seed behaviour, through the experiences of Ceci and Nelson, two visitors from Brazil who are helping us unravel the mysteries of orchid seeds.
13 Mar 2012
Filmed over the course of a year at the Royal Botanic Gardens, Kew, Kingdom of Plants 3D provides a fascinating new look at plant life using stunning 3D time-lapse filming techniques. Own your personal copy today following the DVD and Blu-ray release.
08 Nov 2012
A new study from Kew suggests that Arabica coffee could be extinct in the wild within 70 years.
18 May 2010
Kew’s top propagation ‘code-breaker’, horticulturist Carlos Magdalena, has cracked the enigma of growing a rare species of African waterlily. The 'thermal’ lily (Nymphaea thermarum) is believed to be the smallest waterlily in the world, with pads that can be as little as 1 cm in diameter.