10 Things You Should Never Eat in the Wild

Yes, there are many edible mushrooms growing in the great outdoors. Experts say there are several thousand edible species in North America alone. But there are many poisonous ones, too — some 250 species in this same continent [source: Oder]. Unless you're a mushroom expert, it's best to leave these fungi alone and pick up your 'shrooms in the grocery store. Even if you think you've got a pretty good grasp on which ones are edible and which are not, keep in mind that there are more than a few poisonous mushrooms that closely resemble popular edibles.

One example is the green-spored parasol. This is the most commonly ingested poisonous mushroom in North America. Why? When young, green-spored parasols resemble those white button mushrooms we see on pizzas, in salads and at the market.

Then there are the prized morel mushrooms, which have an evil twin in toxic "false morels"; ditto with the tasty chanterelles, which look an awful lot like the poisonous jack-o'-lantern mushrooms. So be safe and don't nosh on any mushrooms you find growing wild [source: Oder].

We know, we know — water isn't something edible. Still, it bears discussion under this topic, as thirst can be a powerful motivator. If you didn't carry enough H2O on your hike, don't think you can dip into a pool of stagnant water to quench your thirst. Such water may seem fairly innocuous, especially if it's not covered with a slimy green coating. And certainly taking a long sip from a pool of stagnant water may seem better than going without, especially if it's quite hot out or if you haven't had a drop to drink in a long time. But there are definitely some risks in doing so.

Any pool of stagnant water, or even an area of slow-flowing water, attracts innumerable insects wishing to breed. Top among these are mosquitoes, which are well-known for transmitting serious diseases, such as malaria, dengue and West Nile virus [source: WHO].

Skip the standing water, then, and soldier on until you find a more reliable source of water, like a running stream. Better yet, always make sure to carry plenty of water when you'll be outdoors for a while.

The name says it all: poison ivy. Why in the world would you try to go near something with "poison" in its name? Perhaps because you thought it was something else. Poison ivy can resemble other harmless creeping vines. The plant produces an oil — urushiol — that's a known skin irritant. If you touch it, you can get a terrible, blistering rash that can last quite a while. Further, once you've been exposed, you can become allergic to it [source: WebMD].

At some point, someone thought that perhaps eating poison ivy would help people develop immunity to it. In 1987, a study was done on this — severe irritation of your mouth, throat or your intestinal lining. Plus you can come down with everything from nausea and vomiting to fever and death [source: WebMD].

Who doesn't love a plump cherry tomato? If you think you see one growing in the scrub during a hike, though, don't pluck it and eat it. It's likely not a cherry tomato at all. Wild tomatoes don't grow in the U.S.'s lower 48 states, for one thing, although they do in other parts of the globe such as southern Ecuador and northern Peru [source: TakePart]. What's more concerning is that the tomato family contains numerous wild relatives that can be quite harmful if eaten. Horse nettle is one of them [source: MacWelch].

Horse nettle fruit is typically yellow or green in color, and shaped like a cherry tomato. It's especially worrisome if someone stumbles upon it in the winter. During that season, the plant itself is dead, yet its fruit often looks appealing and is still quite juicy. But if you pop one in your mouth, you can be in for abdominal pain and breathing difficulties — certainly not anything to mess with [source: MacWelch].

Rhododendrons are sometimes called the King of Shrubs because these flowering evergreen plants thrive in temperate landscapes. Large and leathery-leafed, rhododendrons sport pretty clusters of red, white, pink or purple flowers. Unfortunately for those looking for a snack in the wild, every bit of a rhododendron is toxic. The leaves in particular are dangerous. Chomping on some rhododendron can lead to stomach irritation and abdominal pain. Even worse, it might cause an abnormal heart rate, convulsions, coma and perhaps death [source: The Flower Expert].

Interestingly, those who have become sick from rhododendron poisoning usually have eaten honey crafted from the plant's nectar. Such rhododendron poisoning occurred as long ago as 400 B.C.E., when written records mentioned a "honey intoxication" that sickened 10,000 Greek soldiers who had eaten honey made from rhododendron nectar.

The plant is toxic to other animals as well; some dub rhododendron "lambkill" and "calfkill" because these young animals are unaware of its dangers, and sometimes perish after eating large quantities of leaves or flowers [source: Hoyum].

Colorful lionfish, native to the Pacific Ocean, have a voracious appetite. In recent times they've been taking over Caribbean waters, where they wreak havoc on the reef ecosystems. (No one is sure how they got there, but the leading theory is that the fish were dumped out in the sea by aquarium owners). To combat this problem, the National Oceanic and Atmospheric Administration (NOAA)advocated eating lionfish to help get rid of them. Yes, these fish have venomous spines, NOAA officials admitted, but if you removed those, the fish were quite delectable and safe to eat [source: Aleccia].

Don't be quick to follow NOAA's advice. Some 200 lionfish were tested in 2010 by the Food and Drug Administration (FDA) after the NOAA issued its proclamation, and more than 25 percent were found to have unsafe levels of a toxin that can cause ciguatera, a fish-based food poisoning. If you nosh on lionfish, you risk not only the typical food poisoning symptoms (diarrhea, vomiting, fatigue), but also neurological problems. The latter includes tingling in the hands and feet, the feeling that your teeth are loose and a reversed sense of temperature [source: Aleccia].

Don't think ciguatera is an anomaly, either. About 50,000 cases of ciguatera are reported annually around the globe, although experts say the true figure could be as much as 100 times higher [source: Aleccia].

You might associate holly mainly with a wreath you hang at Christmastime. But there are many species, some of which grow wild. The bright red berries might look inviting but you'll want to stay clear of them as they can cause nausea, diarrhea, vomiting and possibly death.

The leaves, however, are another story. Indians from North and South America have used the leaves of some varieties of holly for medicinal purposes for centuries. The holly species Ilex vomitoria helped induce vomiting, while the Ilex opaca variety was a heart stimulant. Teas from holly leaves have also been involved in combating everything from simple coughs and water retention to joint pain, chest congestion and high blood pressure. They've even been used to cleanse the bowels and increase urine flow [source: WebMD].

Despite such widespread use in certain parts of the world, experts say it's still risky to ingest holly leaves, which can cause diarrhea, nausea and vomiting [source: WebMD].

Imagine you're lost in the forest and the only bit of protein you spot is a bat. Assuming your trapping skills are good, should you go for it? It's true that people around the globe eat bat meat. One reason why is that it's a great source of protein, one that can be smoked or added to soups. However, bats host more viruses than any other mammal on Earth. In fact, it's believed that the Ebola outbreak of 2014 came from bats in West Africa [source: Osborne]. The real danger is not so much from eating bats but from being bitten or scratched by them during hunting or from coming in contact with their bodily fluids during cooking and preparation [source: CDC].

Ebola is not the only disease bats have been linked to. Guam's Chamorro population suffered from high rates of a strange neurological illness that, eventually, was traced to the people's consumption of the Mariana flying fox, a type of bat. This mammal, through its habit of eating seeds from cycad plants, obtains neurotoxins and thus becomes dangerous for human consumption [source: Pickrell]. The smart thing? Leave bats alone.

There are many edible flowers, such as marigolds, carnations and bee balm. But don't think you can pluck any comely blossom and pop it into your mouth. Several are harmful, including foxglove. Also known as fairy bells, rabbit flower, throatwort and witches' thimbles, foxglove grows to about 3 feet (1 meter) tall. It sports purple, pink or white flowers set along a central stalk. Its leaves are important to the medical industry, as they're used to make the heart drug digitalis. (Digitalis gets its name, incidentally, from foxglove's Latin name: Digitalis purpurea) [source: Lloyd].

But don't eat foxglove blossoms, its leaves or any part of this plant. If you do, you'll most likely develop nausea, vomiting, cramps and diarrhea. Your mouth will probably hurt, too. Perhaps the most dangerous thing is that the plant can affect your heart rate, thanks to the same components that make it great for producing digitalis [source: Lloyd].

The Greek philosopher Socrates is famed for being sentenced to death by drinking poison hemlock tea. So you should have a pretty good idea that ingesting hemlock isn't the smartest idea. The herbaceous plant, which is a member of the parsley family, is a tall biennial with a thick taproot and purple-spotted stems. It produces clusters of small, white flowers. Its leaves are often mistaken for wild parsley and its roots for parsnips.

While it's dangerous to consume any part of the plant, the deadliest section is the seeds, which contain coniine, a toxic alkaloid. Although poison hemlock is native to Eurasia, it was introduced to North America and is now found along its waterways and disturbed sites, much like common weeds.

So what happens if you eat this plant? You'll likely have the typical poisoning symptoms, such as vomiting, weakness and trembling. But hemlock poisoning also depresses the central nervous system and can put you in a coma. If you're unfortunate like Socrates, it can also kill you [sources: Encyclopaedia Brittanica, Weed Science Society of America].