What to know about Nerium oleander (oleander) before using it medicinally

Nerium oleander, commonly known as oleander, is a herb that has been prized for its health-promoting properties, which have been shown to improve heart health, reduce inflammation, and alleviate symptoms of anxiety and depression.

This versatile herb is also a popular choice for gardeners, as it is relatively low-maintenance and can thrive in a variety of conditions. From a botanical perspective, Nerium oleander is a shrub-like plant that belongs to the Apocynaceae family and is characterized by its glossy leaves and showy flowers.

The use of oleander has been documented throughout history, with ancient civilizations such as the Egyptians and Greeks utilizing it for medicinal and ceremonial purposes.

This article explains the medicinal, horticultural, botanical, and historical aspects of Nerium oleander.

What are the medicinal properties of Nerium oleander?

Nerium oleander helps with treating various ailments, including cardiovascular conditions, such as high blood pressure, and gastrointestinal issues like diarrhea and dysentery. It is also used to treat fever, rheumatism, and skin conditions like eczema and acne.

The active constituents of Nerium oleander that give it its medicinal properties include cardiac glycosides, specifically oleandrin and neriine. These compounds have been shown to have cardiotonic and inotropic effects, meaning they can strengthen heart contractions and improve cardiac function.

The most commonly used parts of the Nerium oleander plant for medicinal purposes are the leaves and flowers. The leaves are rich in cardiac glycosides, while the flowers are used to treat skin conditions and fever. The plant's roots and bark are also used, but to a lesser extent.

Using Nerium oleander improperly can lead to side effects like nausea, vomiting, diarrhea, and abdominal pain. In severe cases, it can cause cardiac toxicity, resulting in irregular heartbeats, shortness of breath, and even cardiac arrest.

Precautions when using Nerium oleander medicinally include using it only under the guidance of a healthcare professional, as the plant's toxicity can be severe. Additionally, individuals with pre-existing heart conditions, pregnant or breastfeeding women, and children should avoid using the plant entirely.

What are the horticulural aspects of Nerium oleander?

Nerium oleander grow best in well-draining soil with full sun and temperatures between 40-100°F (-40-38°C). They can thrive in poor soil, but optimal growth is achieved with moderate to high water and nutrient levels. Average annual rainfall is sufficient.

Planting tips for Nerium oleander involve digging a hole slightly larger than the root ball, about 6-8 hours before planting to allow soil to settle. Water thoroughly and fertilize in early spring and summer months with a balanced, water-soluble fertilizer.

Harvesting tips for Nerium oleander flowers are typically done when blooms are fully open, usually in late spring to early summer. Cut branches, not the entire plant, to encourage new growth. Pinch off buds that are not yet open to redirect energy to fully blooming flowers.

Pests affecting Nerium oleander include scale insects and whiteflies, while diseases include root rot, leaf spot, and stem canker. Regular pruning and water management practices help prevent root rot. Leaf spot and stem canker are often caused by overwatering or poor air circulation.

What are the botanical aspects of Nerium oleander?

Nerium oleander is a flowering shrub or small tree with a broad, rounded crown and a single, smooth, gray trunk that can grow up to 15 meters in height. It has dark green, oval-shaped leaves that are 5-17 cm long. White or pink fragrant flowers are borne in clusters.

Nerium oleander belongs to the family Apocynaceae, and its taxonomic classification is as follows: Kingdom: Plantae, Clade: Angiosperms, Clade: Eudicots, Order: Gentianales, Family: Apocynaceae, Genus: Nerium, Species: N. oleander. There are several species within the genus, but N. oleander is the most widely cultivated.

Several variants of Nerium oleander have been developed for ornamental purposes, including 'Stenophylla', 'Pallida', 'Rubra', and 'Limeira'. These variants differ in flower color, leaf size, and growth habit, but they are all derived from the original species. 'Stenophylla' has narrower leaves, while 'Pallida' has pale yellow flowers.

Nerium oleander is native to the Mediterranean region, but it has been widely cultivated and naturalized in many parts of the world, including Australia, the Americas, and Africa. It grows best in warm, dry climates with full sun and well-drained soil. It is often used as an ornamental plant in gardens and landscapes.

The life cycle of Nerium oleander begins with seed germination, which occurs within 2-6 weeks after sowing. The seedling grows rapidly, producing leaves and flowers within 6-12 months. It flowers repeatedly throughout the year, producing white or pink flowers that attract pollinators. The flowers are followed by seed capsules that disperse the seeds, completing the life cycle.

What are the historical aspects of Nerium oleander?

Nerium oleander is an ancient plant with a rich history of medicinal, cosmetic, and decorative uses. In ancient Greece and Rome, it was used to treat various ailments, including fever, rheumatism, and snake bites. Its extracts were also used in perfumes and ointments.

In Greek mythology, oleander was associated with the goddess of love, Aphrodite, and the god of beauty, Adonis. According to legend, the plant was created from the blood of Adonis. The Greeks and Romans also used oleander in funeral rites to ensure the deceased person's safe passage into the afterlife.

Throughout history, oleander has held various symbolic meanings. In ancient Greece, it symbolized eternal youth and beauty, while in medieval Europe, it was associated with purity, innocence, and chastity. In some Asian cultures, the plant is seen as a symbol of love and passion.

The historical texts provide valuable insights into the use and cultivation of oleander. The Greek physician Dioscorides wrote about the plant's medicinal properties in his book "De Materia Medica" (circa 50 AD). Similarly, the Roman naturalist Pliny the Elder mentioned oleander's uses in his book "Naturalis Historia" (circa 77 AD).

Oleander has also appeared in various historical artifacts, including ancient coins, pottery, and textiles. In some of these artworks, the plant is depicted in association with the gods or as a symbol of eternal youth and beauty. For example, the ancient Greek amphora from the 5th century BC features an image of oleander alongside the goddess Aphrodite.