Beyond Arsenic: 6 Weird Poisons Used Throughout History

Two species of the Gelsemium family — G. sempervirens and G. rankinii — are vining shrubs that spend part of their growing season covered in cheerful yellow flowers. They're a popular plant in North American landscaping, where they become prolific bloomers with a minimum of care. A third species native to China and Southeast Asia, G. elegans, has the same good looks, but far more sinister underpinnings.

Although all the species are poisonous to humans, G. elegans is known colloquially as "heartbreak grass" because of its suicide-assisting history. Gelsemine, a toxic compound concentrated in its roots and leaves, is a fast-acting poison that causes a storm of seizures and convulsions before it paralyzes the spinal cord and lungs, and ultimately, leads to asphyxiation. Gelsemine has been suspected of several nefarious deaths, including the 2012 death of Alexander Perepilichnyy, a Russian expat with finance ties to organized crime.

"Spanish fly" is a poison not related to flies at all — and it won't increase one's sex drive, as a longstanding urban legend goes. Rather, it comes from the Lytta vesicatoria blister beetle, and even the slightest contact with its secretions (a substance called cantharidin) will make your skin erupt into painful blisters. This comes in handy when used to rid the skin of warts in a controlled medical setting.

But ingest only a small amount of cantharadin and it will eat away your stomach, cause your abdominal cavity to fill with blood and inflame your urinary tract. And this is where the sex drive myth comes into play. As cantharidin destroys the innards, it kicks off massive inflammation that leads to engorged external organs — including the penis. So that long-term penile erection is neither pleasant nor productive; it's a painful and debilitating health crisis, and doesn't affect desire.

Venom-based Chinese poison, whether derived from scorpions, snakes, centipedes, spiders or toads, is known collectively as gu. It's historically made by putting a variety of venomous animals in an enclosed container and letting them duke it out. The surviving animal, which was believed to contain concentrated venom imparted during the fight, was killed, ground into a paste and used as a slow-acting poison that took up to two weeks to kill its victims.

This timeline fit perfectly with the lore surrounding discouraged social actions. Women from China's southwest frontier were rumored to use the poison on visiting lovers, giving them just enough time to return for an antidote before they died. The truth is, there weren't widespread gu poisonings. The stories were used to spark fear and prejudice, and encourage China's northerners to steer clear of the minority cultures in the country's south.

Ricin is the toxic protein in castor beans that grow on the tropical African plant Ricinus communis, and is released when the bean is chewed or when it is dried and ground into a powder. Ricin was famously implicated in the 1978 murder of Bulgarian dissident Georgi Markov, who was poked by a ricin-tipped umbrella while on the Waterloo Bridge in London. More than 30 years later, a suspect was finally named — a former Bulgarian spy quietly living in Austria.

As little as one milligram of ricin can be fatal for an adult, but before death comes vomiting, bloody diarrhea and abdominal pain. Despite these risks, castor beans can be swallowed whole without effect and the plant is grown in gardens and homes throughout the world.

How was guilt or innocence determined before the modern justice system was put in place? As late as the mid-19th century, a person's fate sometimes was determined by a single bean. Yes, a bean. The calaber bean is the kidney-shaped harvest of a climbing legume native to Nigeria with a name reminiscent of the Harry Potter universe: Physostigma venenosum. It contains a physostigmine alkaloid compound that acts like a nerve gas, and causes seizures, excessive saliva, loss of bowel and bladder control, and ultimately, asphyxiation.

This little but deadly bean is also called the "lie detector bean" or the "ordeal" bean for its historic use in "trial by ordeal" proceedings, in which the accused would be forced to eat the beans. Those who lived were innocent. Those who died were guilty, so good riddance. Today, the bean is being studied for its potential to reverse Alzheimer's and dementia.

Thallium is an ingredient in rat poison and insecticide, but it's also a crucial part of green-colored fireworks, imitation jewelry and electronic components. Because thallium, a heavy metal, is colorless, tasteless and odorless, it's been a historical go-to for poisoning. From classically trained chemists to regular people buying rat poison at the corner market, thallium has been logged in too many murder case files to count.

Large doses of thallium cause vomiting, abdominal pain and diarrhea, as well as damage to nerve endings that make affected people feel like they are walking across a bed of burning coal. It causes loss of control to the bowel and bladder, and in the end, a heartbeat so irregular that it brings death. Even small doses, especially over an extended period of time, can be extremely damaging and result in death.