The World's Deadliest Tree

Guinness World Records has named it the world's deadliest tree. The manchineel (Hippomane mancinella) belongs to the Euphorbia family, a very large and diverse genus of flowering plants that also contains the colorful Christmas poinsettia. Its name means little apple that makes horses mad. Many gardeners know all too well that euphorbias contain a milky latex sap that is highly toxic and can be extremely irritating to the skin and eyes.

Manchineel is native to Florida, the Caribbean, Bahamas, Mexico, Central America, and the northern part of South America. It can be found on coastal beaches and in swamps where it grows among mangroves. It provides excellent natural windbreaks and the roots stabilize the sand, helping to prevent beach erosion. Due to its toxicity, manchineel trees have never been considered a major supply of wood for woodworking. Even firewood gatherers leave it alone because the poison will linger in the smoke of burning manchineel.

Identifying the Manchineel Tree

The evergreen tree has reddish-gray bark, small greenish-yellow flowers, and shiny green leaves. The leaves are simple, alternate, very finely serrated or toothed, 2–4 in inches long. Spikes of small greenish flowers are followed by fruits similar in appearance to an apple. They are green or greenish-yellow when ripe. The fruit can be extremely poisonous, as is every other part of the tree.

Symptoms of Manchineel Poisoning

All parts of the manchineel contain strong toxins. Some of them have still not been identified. The milky sap contains phorbol and other skin irritants that produce strong allergic contact dermatitis. Standing beneath the tree during a rain will cause blistering of the skin from mere contact with the liquid. Even a small drop of rain containing the milky substance will cause the skin to blister. The sap has also been known to damage paint on cars. Burning the tree can cause eye injuries if the smoke gets in them. Contact with its sap produces bullous dermatitis, acute keratoconjunctivitis, and possibly corneal defects.

The fruit is potentially fatal if eaten; however, fatalities from ingestion have not been reported in the modern medical literature. Ingestion can produce severe gastroenteritis with bleeding, shock, bacterial superinfection, and the potential for airway swelling and compromise. Patients with a history of ingestion and either oropharyngeal burns or gastrointestinal symptoms should be evaluated for admission to a hospital.

The fruit is said to taste pleasantly sweet initially, changing to a subsequent strange peppery feeling that gradually progresses to a burning, tearing sensation and tightness of the throat. Symptoms continue to worsen until the patient can barely swallow solid food because of excruciating pain and the feeling of a huge obstructing lump in the throat.

Removing a Manchineel Tree Safely

Removing a manchineel tree from a populated area is problematic. Cutting the tree releases the sap, and burning the tree turns the toxins into a vapor that’s carried in the smoke. Even contact with the smoke can leave burns on the skin and sometimes results in blindness.

In Curaçao many trees carry a warning sign; others are simply marked with a red "X" on the trunk to indicate danger. In the French Antilles the trees are often marked with a painted red band a few feet above the ground. The trees on Bonaire are unmarked.

Manchineel Herbal Medicine

The dried fruits are occasionally used as a diuretic. In Jamaica, manchineel tree gum has long been used to treat various venereal diseases. A species of Central American iguana is completely immune to the poisonous qualities of the tree and often lives among its branches. Although the plant is toxic to many birds and other animals, the black-spined iguana (Ctenosaura similis) is known to eat the fruit and live among the limbs of the tree.

(Photo: Mica [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)], from Wikimedia Commons)

A poultice of arrowroot (Maranta arundinacea) was used by the Arawak and Taíno people of the Caribbean as an antidote against manchineel poison. The Caribs were known to poison the water supply of their enemies with the leaves. Spanish explorer Juan Ponce de León died shortly after an injury incurred in a battle with the Calusa in Florida after being struck by an arrow that had been poisoned with manchineel sap.

Uses of Manchineel Wood

Oddly enough, in some places the wood of the tree is highly prized for making furniture such as the cabinet shown below. Once the wood has been left to dry in the sun, its poisonous qualities largely disappear. Despite the inherent dangers associated with handling it, the tree has been used as a source of timber by Caribbean carpenters for centuries. It must be cut and left to dry in the sun to remove the sap. A gum that reportedly treats edema can be produced from the bark, while the dried fruits have been used as a diuretic.

(http://www.arcarta.com/product/collection/casepieces/3584/an-unusual-george-ii-manchineel-architectural-breakfront-cabinet)

When the Spanish conquistadors arrived in the Florida Keys, the local Indians fought back with everything at their disposal, including the poisonous sap of the manchineel which they used to contaminate water supplies. One Spaniard noted, "He who sleeps under a manchineel sleeps forever"[1].

[1] https://www.woodmagazine.com/materials-guide/lumber/wood-species-2/manchineel; http://www.guinnessworldrecords.com/world-records/most-dangerous-tree