Not all nuts are created equal, and while almonds might be good for you, they’re also on Mashed’s list of nuts you should avoid, strictly because of the devastating impact almond farms have on the environment. There’s another really good reason not to go eating almonds all willy-nilly, and that’s because some are downright deadly. Healthline says that raw bitter almonds — the same kind one might use for baking, or to make almond paste — contain something called glycoside amygdalin. Eat a few, and they’ll make a person super sick. Eat a couple handfuls, and they’ll be absolutely deadly to an adult, because when this toxin hits the digestive system, it reacts to form hydrogen cyanide.

NPR tells a fascinating story about early attempts at domesticating these almonds and removing the cyanide. Way back in the 4th century, St. Basil wrote that if a hole was drilled into an almond tree and a piece of pine was inserted, the almonds would be safe to eat. Sounds unlikely, right? It totally worked: Today, scientists believe the stress of the procedure caused the tree to reroute energy from the production of toxins into survival mode.

There’s not that much difference between the bitter almonds that can kill a child who eats just a couple of them and the sweet almonds used on Christmas cheese balls across the country: Just a single genetic mutation gave us the edible ones.

Quick, name something that’s better than a frozen lychee margarita. Can’t, right? Unfortunately, while they might be delicious, they’re also kind of deadly. According to the BBC, something terrible had been happening in India’s Bihar region on an annual basis. Every year — for decades — otherwise healthy children would suddenly suffer seizures, loss of consciousness, and in about 50% of the cases, death followed soon after.

For years, no one had been able to figure out what was going on, until researchers started looking at lychees as the potential catalyst in hundreds of deaths. Lychees, it turns out, contain a toxin that interferes so completely with the body’s glucose production that children who swiped a few fallen lychees in lieu of dinner were stricken with acute swelling of the brain just a few hours later.

The link was discovered in 2017, and children continued to die. In 2019, CNN reported that officials had learned a little more about what was going on, and suspected there’s some connection between high temperatures, the malnutrition that often goes hand-in-hand with poverty, unripe lychees, and toxins that build up in the liver until the human body just sort of reaches a breaking point.

Wolfsbane, says the Chicago Botanic Garden, shows up in countless works of fantasy and horror. As far back as ancient Greece, this pretty bluish-purple flower was connected with dogs: It was said to have first sprouted from the drool of Cerberus, Hades‘ three-headed guardian. Strangely, it’s not just werewolves that have a very bad reaction to it — it’s incredibly deadly to people, too.

Wolfsbane is one specific species in a group of plants called Aconitum, and the BBC says that other closely-related species called the Devil’s Helmet, Monkshood, and the Queen of Poisons are all just as deadly. Eating the leaves will cause severe sickness, but it’s the roots that are the most toxic: If those are ingested, heart failure and death typically happen in just a few hours.

Strangely, these plants remain a super popular addition to gardens, and John Robertson of the Poison Garden says it’s the most dangerous plant that people tend to voluntarily plant in their garden. There’s an important footnote to this, too: It seems as though some people don’t have to ingest the plant to be killed by it. In 2014, a gardener named Nathan Greenway died after handling the plant on his boss’s estate. The BBC reported that the cause of his death was multiple organ failure, and that it was in line with a fatal dose of toxin from the Monkshood he’d been working with.

When the Greek philosopher Socrates was told he was either going to die or stop carrying out his public lectures, he chose to die. He also chose the method: drinking tea with hemlock. According to “The Big, Bad Book of Botany: The World’s Most Fascinating Flora” (via Slate), accounts of Socrates’s last moments were probably exaggerated. After drinking hemlock, there would have been a lot less of reminding his assistants to settle old debts and a lot more struggling to breathe.

There are a few different types of hemlock, says the U.S. Forest Service. It was the aptly-named poison hemlock that Socrates drank, but that species’ close relative, the water hemlock (pictured), is just as deadly. It doesn’t take much to kill either animals or people, and anyone unfortunate enough to take a bite will suffer from things like seizures, vomiting, abdominal pain. It’s all typically followed by death within an hour of eating it. The entire plant is toxic, and it’s actually pretty understandable how someone might make a lethal mistake and nom away. It looks a lot like parsley — it’s in the parsley family — but it’s most definitely not parsley.

The Alderleaf Wilderness College says the cause of death from eating hemlock is usually respiratory paralysis, and it can happen as quickly as 15 minutes after ingestion. Given that it’s found in wet areas and pastureland across Europe and North America, it’s highly recommended that when in doubt, foraging nature-lovers should skip the parsley.

Abrin, says the CDC, is a naturally occurring poison that has some brilliant uses. It’s definitely deadly, but when it’s prepared and administered correctly, it’s super effective at killing cancer cells. Way to go, abrin! Unfortunately, there’s a downside. Abrin is found in the seeds of a plant called the rosary pea, and these neat-looking black and red seeds are often used to make jewelry… and anyone who’s ever made or been in the vicinity of a toddler knows where this one’s going.

Swallowing the seeds of the rosary pea can definitely lead to some major problems — and to make things more complicated, they’re problems that might not even show up for a few days. Abrin enters a person’s cells, and gradually starts shutting things down. Within a few days, that can lead to things like seizures, hallucinations, and finally, organ failure.

The National Capital Poison Center says there hasn’t been much research done on just how many seeds someone needs to swallow in order for it to turn deadly, so they say any amount is considered dangerous. There’s no known antidote for abrin and rosary peas, so a safe bet would be to just skip those rosary pea bracelets and go with something that doesn’t come with a free risk of death.

It grows along India’s southwest coast and in Madagascar, and while it’s properly called Cerbera odollam and less formally called othalanga, it’s sometimes referred to as the suicide tree. That’s because the seeds it bears (pictured) are almost unthinkably deadly — so deadly that in the 19th century, Madagascar authorities would give accused criminals and witches the seeds to eat. If they didn’t die, they were innocent, and if they did die, they were guilty — and apparently, there were a lot of guilty people in Madagascar.

The Washington Post says that it’s estimated that more people commit suicide by eating the fruits of the othalanga than by eating any other plant, and around 75% of those are women. Strangely, the plant — which is used to make rat poison — hasn’t been studied much, so it’s not clear just how it works. What is clear, though, is that there’s something in it that stops a person’s heart. New Scientist adds that since it’s incredibly hard to detect, it makes such a good and often-used murder weapon that it could just as reasonably be called the murder tree.

Othalanga seeds have been linked to hundreds of suicides in India, but they’re also making their way to the US. In 2016, ABC reported that Natosha Anderson was hoping to raise awareness about the accessibility of the deadly seeds after losing her child to suicide.

If you or anyone you know is having suicidal thoughts, please call the National Suicide Prevention Lifeline​ at​ 1-800-273-TALK (8255)​.

Cherries are delicious, there’s no secret there. But according to Michigan State University, they’re also deadly — to livestock. Here’s how it happens. Black cherry trees have several different compounds that are normally contained in different cells and tissues within the plant. However, when the trees are damaged — as they were during severe storms that swept through orchards in 2017 — the compounds combine to form hydrogen cyanide. And that’s deadly: just over a pound of the leaves would be enough to kill a standard-sized dairy cow.

All grazing livestock is susceptible to this kind of poisoning, and the PennState Extension says that the smaller the animal, the smaller the lethal dose becomes. For a sheep, they’d only need to eat about .18 of a pounds of the leaves for it to turn into a deadly snack.

And it’s an ugly, terrible death that involves things like convulsions, kicking, panting, and drooling. Cherry trees near pastureland are considered a major threat to the health and safety of livestock, and agricultural extensions recommend that all cherry trees should be removed from the vicinity of any grazing animals.

Giant hogweed definitely lives up to the name: It can reach heights of up to 14 feet, and it’s kind of pretty. That’s basically why it’s found in the U.S. and in Europe at all: It’s native to the Caucasus Mountains, and it was spread by early 20th century gardeners who were looking for big, impressive plants to include in big, impressive gardens. Choosing giant hogweed was very, very dumb. The entire plant is filled with a sap that contains toxic components called furanocoumarins. Get that on your skin, and Healthline says that’s what kicks off a chemical reaction called phytophotodermatitis.

According to the New York Department of Environmental Conservation’s Giant Hogweed Program Coordinator Naja Kraus (via Good Housekeeping), “The more sap you touch, the greater damage it causes. Once you get it on you, it makes your skin unable to protect itself from the sun.” The reaction happens on a genetic level — she says, “It basically fuses your DNA in that area.”

What follows are second- and third-degree burns that could require skin grafts, along with the potential for blindness and respiratory problems. Permanent scars are likely, and the increased sun sensitivity can last for months, and the carcinogenic compounds in the plant have been linked to causing cancers as well as birth defects (via BHG). Experts recommend not removing it yourself but calling your state’s department of conservation.