Oleander (Nerium oleander) — ornamental, toxic Mediterranean shrub

Description and key characteristics

Oleander is typically a multi-stemmed shrub that can reach several metres in height. Leaves are lance-shaped, leathery and evergreen, arranged in pairs or whorls. Flowers occur in terminal clusters and vary from white through shades of pink to red and yellow, often with fragrance. The plant exudes a milky sap when cut. Botanical features and identification tips are summarized here: identification guide.

Habitat, cultivation and uses

Valued for low-maintenance landscaping, oleander tolerates poor soils, drought and coastal exposure. It is propagated easily from semi-ripe cuttings and responds well to pruning, making it a common choice for formal hedges, screens and roadside plantings. In suitable climates it can naturalize; local cultivation advice and horticultural notes are available at garden resources and pruning guides: care and propagation.

Toxicity and chemistry

All parts of oleander are poisonous. The plant contains cardiac glycosides (cardenolides) such as oleandrin and neriine, which affect heart function if ingested. Symptoms of poisoning in humans and animals can include nausea, vomiting, abdominal pain, irregular heartbeat and, in severe cases, fatal cardiac effects. Avoid ingestion, and handle cuttings with gloves to prevent sap contact. For medical and veterinary information see toxicology overview and emergency guidance: safety advice.

Research and medicinal interest

Cardenolides from oleander—especially oleandrin—have attracted laboratory research into potential antiviral, anticancer and other biological effects. Such studies are preliminary and do not establish safe or effective medical uses; the therapeutic window is narrow and the compounds are toxic. Any research summaries or regulatory notes should be consulted carefully: research summaries and regulatory comments.

History, cultural notes and precautions

Oleander has a long history in Mediterranean gardening and appears in literature and garden design traditions across its native range. While ornamental, it requires respectful handling: never ingest any part, keep cuttings away from children and pets, and dispose of trimmings safely. Practical safety tips and comparisons with similar species are provided here: safety tips and species comparisons.

• Common uses: ornamental hedge, roadside planting, drought-tolerant landscape.
• Hazard: all plant parts poisonous; seek immediate help if ingestion is suspected.
• Note: research into oleandrin is ongoing but does not replace established medical treatments.