Forbidden Fruit

Getting to know Kerala’s “suicide tree”

The seeds of the othalanga tree, loaded with a highly poisonous toxin, come shielded by a hard fruit. public domain
01 September, 2015

On a Wednesday night in early May, four teenage athletes were rushed to hospital from a Sports Authority of India training centre in the coastal city of Alappuzha, in Kerala. The young women had deliberatly swallowed the poisonous seeds of the othalanga tree, or Cerbera odollam. Police later reported finding a note signed by the four, explaining the act as a response to harassment by other athletes living at the centre. The next day, one of them died.

In the media storm that followed, the othalanga tree was described in uniformly macabre tones—a “suicide tree,” a plant of “ill repute” bringing a “brutal harvest”—and with good reason. Kerala—where the annual suicide rate, at 24.6 deaths per 100,000 people, is more than double the national average—has a long and lethal acquaintance with the species. Yet, as I discovered on a visit to Alappuzha in June, the Othalanga tree is far from ostracised here. It grows freely in nearby salt marshes, and in similar locations elsewhere in south Kerala, and has rooted itself deeply in the local psyche. Many Keralites have a surprisingly easy relationship with the potentially mortal plant.

C Dileep, an assistant professor of botany at the Sanatana Dharma College in Alappuzha, agreed to show me the tree in its natural habitat. From a new fast-food restaurant opposite the college campus, we drove along roads under gathering monsoon clouds, lined with fisherman waving their catch at us in hopes of a sale. We stopped just outside town, at a stretch of road cutting through a backwater. Othalanga trees shot up sporadically along its flank, displaying succulent leaves and dainty white flowers reminiscent of crape jasmine blooms. Mango-like fruits hung low and heavy, bobbing in the wind like yo-yos; I was told they are also called “sea mangoes,” and have inspired a Malayalam phrase with their tendency to wobble before coming to rest: Othalanga pole mariyum, or “Fickle like an othalanga.”

Dileep picked a fruit, and, after several blows with a rock, prised it open to reveal an ovoid seed in a fibrous white shell. This is the seat of a toxin, cerberin, that causes uncoordinated spasms of the heart and eventual cardiac arrest. The seeds are a favoured means of suicide, Dileep said, because they purportedly bring on a painless death. There is also a cultish fascination with them, including in online forums about mystery writing, as perfect murder weapons, since cerberin goes undetected in standard autopsies. No antidote has been found yet. If anyone swallows a seed, doctors can only induce vomiting to try and flush the toxin out.

The othalanga seed’s poisonous traits were documented at least as early as 1914, when Rao Sahib M Rama Rao noted them in his Flowering Plants of Travancore. Rao, then the conservator of forests in the erstwhile kingdom, wrote of the othalanga fruit’s use to kill dogs, and even, curiously, to “deprive them of their teeth.” A rare paper on the seeds’ use for suicide, published in 2004, attributed 537 deaths in Kerala to them between 1989 and 1999. “To the best of our knowledge,” it stated, “no plant in the world is responsible for as many deaths by suicide as the odollam tree.” The French toxicologist Yvan Gaillard, the paper’s lead author, told me over email that othalanga seeds may well have caused “as many homicides as suicides” over the period studied. He based this view on suggestions from a coroner in Kerala, whose suspicions could never be confirmed because no lab in the state could then detect cerberin.

For all the plant’s notoriety, othalanga poisoning is hardly the leading means of suicide in Kerala, and is eclipsed by hanging and ingesting pesticides. Unintentional poisoning by the seeds is extremely rare, which is why Keralites tend not to see the othalanga tree as a source of peril. After my excursion with Dileep, I drove deeper into the backwaters as the afternoon wore on. Sobha Maniradhan was sweeping her yard when I showed up at her gate, and her two-year-old grandson was frolicking in her garden. Maniradhan had two othalanga trees in her backyard. “A child can’t bite into the seed because the fruit is very hard,” she reassured me.

Rather than being an immediate threat, the species is threatened itself. In places, the trees are being crowded out by pollution and urban encroachment. Local botanists are concerned about the species’ future. “It is one of the important backwater trees we have here,” Dileep said. “Not only does it prevent soil erosion, its fruits are also part of the diet of local birds.” Thankfully, there have been no calls for its eradication. Suicide is a problem that requires a “social response,” Gaillard told me. “It is not for humanity to try and control biodiversity.”


Debarshi Dasgupta is a National Foundation for India Media Fellow, exploring linguistic aspects of the Maoist conflict.