Cascabela thevetia


Cascabela thevetia is a poisonous plant native throughout Mexico and in Central America, and cultivated widely as an ornamental. It is a relative of Nerium oleander, giving it a common name yellow oleander, and is also called lucky nut in the West Indies.

Description

Cascabela thevetia is an evergreen tropical shrub or small tree. Its leaves are willow-like, linear-lanceolate, and glossy green in color. They are covered in waxy coating to reduce water loss. Its stem is green turning silver/gray as it ages. Flowers bloom from summer to fall. The long funnel-shaped sometimes-fragrant yellow flowers are in few-flowered terminal clusters. Its fruit is deep red-black in color encasing a large seed that bears some resemblance to a 'Chinese lucky nut.'
Cascabela thevetia is commonly known as Kaneir or Kaner in Hindi language in India. It is effectively drought resistant and tolerant to high temperatures, hence found in various states of India like Bihar, Delhi, Gujarat, Madhya Pradesh, West Bengal, Rajasthan, Tamil Nadu and Uttar Pradesh where semi arid climate is prevalent.

Religious importance

Its bright yellow flowers are used for religious purposes, especially in the worshipping of the Hindu deity Shiva.

Toxicity

All parts of the C. thevetia plant are toxic to most vertebrates as they contain cardiac glycosides. Many cases of intentional and accidental poisoning of humans are known.
The main toxins are the cardenolides called thevetin A and thevetin B; others include peruvoside, neriifolin, thevetoxin and ruvoside. These cardenolides are not destroyed by drying or heating and they are very similar to digoxin from Digitalis purpurea. They produce gastric and cardiotoxic effects. Antidotes for treatment include atropine and digoxin immune fabs and treatment may include oral administration of activated charcoal. Ovine polyclonal anti-digitoxin Fab fragment antibody can be used to treat T. peruviana poisoning, but for many countries the cost is prohibitive.
A few bird species are however known to feed on them without any ill effects. These include the sunbirds, Asian koel, red-whiskered bulbul, white-browed bulbul, red-vented bulbul, brahminy myna, common myna and common grey hornbill.
In South India and in Sri Lanka swallowing the seeds of , Manjal arali is one of the preferred methods for suicides in villages where they are grown in abundance.
Extracts from C. thevetia are reported to possess antispermatogenic activity in rats.

Uses

;Cultivation
Cascabela thevetia is cultivated as an ornamental plant, and planted as large flowering shrub or small ornamental tree standards in gardens and parks in temperate climates. In frost prone areas it is container plant, in the winter season brought inside a greenhouse or as a house plant. It tolerates most soils and is drought tolerant.
;Biological pest control
The plant's toxins have tested in experiments for uses in biological pest control. T. peruviana seed oil was used to make a 'paint' with antifungal, antibacterial and anti-termite properties.

Etymology

'Cascabel', 'cascavel' or 'cascabela' is Spanish for a small bell, a snake's rattle or a rattlesnake itself. The allusion may also be to the plant's toxicity comparable to the venom of a rattlesnake. The specific name 'thevetia' commemorates André de Thevet, a French Franciscan priest and explorer, who explored Brazil.

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