When it comes to murder mysteries, we typically don’t consider trees when trying to figure out who the killer might be. Perhaps that’s just one of the reasons it has taken so long to properly recognize the Cerbera odollam as “The Killer Tree.”

Native to Southeast Asia and India, the Cerbera odollam is a medium-sized hardwood tree. Outwardly, there is nothing particularly ominous about it. It can grow to 10 meters (32 feet) in height. Its white flowers are rather pretty. It isn’t until you get to the seeds of its fruit that you find the killer hidden inside this tree. One of the seeds is sufficient to kill a grown person. Once ingested, the seed is virtually guaranteed to produce death. What’s even more sinister is that the cause of death is likely to be undetectable.

Commonly known as the Pong Pong tree, the Cerbera odollam produces a toxin that interferes with the calcium ion channels in the heart muscles. Within one to two days of eating one of the seeds, symptoms of violent vomiting and severe abdominal pain accompany increasingly-irregular and slowing heartbeat until coma and death bring and end to the suffering.

Aside from how lethal the toxin is, the most sinister aspect is that it is difficult to detect the poison in autopsies. A 2004 study determined in the years between 1989 and 1999, the poisonous seeds were responsible for roughly one death per week in the region of Kerala, India. While most of the deaths investigated were suicides, there is good reason to believe many more deaths by homicide can be attributed to the fatal flora. This has earned the Cerbera odollam the nicknames of “The Suicide Tree” and “The Murder Tree.” Researchers believe that more people have taken their own life using Cerbera odollam seeds than any other plant in the world.

Testing for cerberin poisoning is costly. It requires the use of “high-performance liquid chromatography coupled with mass spectrometry,” which isn’t even a viable option in some locations. In fact, toxicologists won’t perform the test unless there’s already strong evidence that the victim consumed the toxin recently. That assumes anyone in that particular area has even heard of the plant.

Aside from its use as a killer of humans, the fruits of the Cerbera odollam are used for such varied purposes as bio-insecticides, biodiesel, and even deodorants.

Read about the man who was poisoned, frozen, beaten, run over, and just refused to die.

Read about another plant that has been classified as the world’s deadliest plant.