Beware of the Oleanders

Gerald McCormack, CINHT

Yellow Oleander, Leaves, flower and fruit – Gerald McCormack

Yellow Oleander is an ornamental tree from tropical America, which is widespread in the Southern Cooks. It has yellow, funnel-like flowers, which develop into angular fruit, about 5cm across. The tree has attractive hanging foliage and grows to about 5 metres in height.

The scientific name is Cascabela thevetia, although you’ll find it in most books under its former name, Thevetia peruviana.

In English, the Yellow Oleander also known as the Be-still Tree. As the foliage and flowers move in the slightest breeze it is easy to imagine photographers yelling “Be-still!” However, this is not how it got its unusual name. The unlikely name, Be-still Tree, is a macabre reference to the ability of the plant to kill people. All parts of the plant, especially the seeds, are deadly poisonous.

A case from Brisbane reported that a 3-year-old girl ate some unknown parts of Yellow Oleander, probably the seeds, in the late afternoon. She suffered a cardiac arrest in the ambulance and was dead by 11pm. A single seed can kill a small child.

The signs of Yellow Oleander poisoning are nausea, vomiting, diarrhea, high blood pressure and irregular heart beat. Death results from cardiac arrest.

Pink Oleander, Leaves and flowers – Cook Islands, Rarotonga – Gerald McCormack

Early vomiting is a blessing as it often removes sufficient material from the stomach to avoid death. However, if you suspect that a child has eaten any part of Yellow Oleander, immediately seek assistance from a doctor.

The more common Pink Oleander (Tärona, Oleander nerium), or Rose-bay Tree, is equally poisonous. Fortunately, its deadly nature is well known and it does not have such interesting fruit to attract the attention of young children. Nevertheless, a single leaf is potentially lethal, and heat does not destroy the poison.

In Australia there was a case of a woman dying after mistakenly making a herbal tea of oleander leaves; and in another case, several people were rescued unconscious from a smoky room, where they were burning oleander wood to keep warm.

Author’s notes
First published CINEWS (9 October 1993)
Gerald McCormack

Posted by Gerald

Gerald has worked on Cook Islands marine and terrestrial biodiversity since 1980. He was the foundation Director of the Natural Heritage Trust since 1990

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