Oleander (
Nerium oleander) is a highly toxic evergreen shrub or small tree in the dogbane (Apocynaceae) family. It has distinctive and beautiful large, usually pink or red flowers. Oleander is native to the eastern Mediterranean region, northern Africa, Middle East and southeast Asia, however it is planted in many subtropical and tropical regions worldwide. Oleander is a drought-tolerant plant that grows best in dry, warm climates. It is often used for hedging, beach and roadside plantings, colorful accents and yard landscapes, and screens.
Oleander Toxic Components
Oleander contains several cardiotoxic compounds and is responsible for numerous poisonings in ruminants. The primary toxin is oleandrin, a type of cardiac glycoside. Cardiac glycosides are known for inhibiting Na+/K+ ATPase, causing heart arrhythmias which lead to cardiac arrest and death. All parts of the oleander plant are toxic, however most cases of poisoning in animals involve ingestion of the leaves. Ruminants don't need to ingest very much to have fatal consequences. As little as 0.005% of their body weight in dry oleander leaves can be fatal.
What Oleander Looks Like
- Presentation: Oleander can be managed to grow as a single or multi-branched evergreen tree or shrub.
- Leaves: Smooth, dark green, thick and leathery. Lance-shaped. Long and narrow, often between 5 to 21 cm (2 to 8 in) in length, dwarf varieties may be shorter. Often grow in whorls.
- Flowers: 5-petaled, funnel-shaped clusters of flowers grow at the end of each branch. They have a pleasant fragrance and the color can be various shades of pink, white, red, yellow, orange, or purple.
- Fruit: Long narrow capsules 2 to 9 in (5 to 23 cm) long. The capsules split open once mature and release numerous fuzzy seeds
- Height: 6 to 20 feet (2 to 6 m)
- Spread: 10 to 16 feet
- Bark and stems: Erect stems which splay outward as they mature. First-year they grow the stems have a glaucous bloom, however once mature have a grayish bark. If the stems are cut, they exude a sticky latex substance.
