A character is in a very nature-oriented setting, with all kinds of wild plants surrounding them. They're doing whatever it is they planned to do, and at some point pick up or walk into an ordinary-looking plant. After a small amount of contact with it, someone who is more knowledgeable about nature will casually inform them "That's poison ivy" (or poison oak, the plants have the same toxin).
Note: These are generally Played for Laughs. If you're weak of stomach, do not look up the types of injuries these plants can create (Unless you'd really like to see an example of a blister the size of a football). Oh, and poison sumac, if burned, releases a gas that causes allergic reactions that can kill. It really pays to know your plants before you go hiking.
- In Monster Musume, protagonist Kimihito's very low on funds for food to feed his Unwanted Harem. Part of his hunt for food leads him into a forest filled with both edible plants and very poisonous ones. He was originally going to give up on the plants altogether, but Suu proved she could safely distinguish between the poisonous plants and the ones that were safe to eat.
- Archie Comics:
- One story ends with the revelation that the corsage Archie gave Veronica to wear at the prom was poison ivy.
- Oh, it gets worse. There is another comic where Archie loses his shorts in a swimming hole, and Jughead makes him an impromptu grass skirt out of nearby vines. Yep — they turn out to be poison ivy.
- Lehrigen has been commissioned by the Djun to bring him an elven healer. It's the dead of winter when Lehrigen and his hunters reach the current Holt of Ember and her tribe; Ember gives instructions to try and drive the humans away, preferably without hurting them. Cue fairy tale pranks. But then Teir and Mender come up with something darker: Assuring Ember that it's perfectly harmless and will only irritate the humans, they leave dry itchleaf vinesnote in a neat pile; the humans find them while looking for kindling. One of the humans suffocates to death after breathing the smoke. Ember is beyond pissed when she finds out Teir and Mender lied to her. Lehrigen is angry with the elves, but he also chews out the survivors for being so stupid as to fall for the bait in the first place.
- Subverted in the first Blue Mountain arc. Every Wolfrider worth their survival skills knows what strangleweed looks like, the way it grows low to the ground, looks like a thick mass of green tentacles, and how it will grab anything that comes near it and choke the life out of it. What they aren't expecting is to find it in 1) in vine form 2) woven into a suspended net 3) in the depths of the caverns of Blue Mountain.
- In an early issue of Sonic the Hedgehog (Archie Comics), Sonic was picking flowers to bring to Sally, only for a random background character to wander by and inform him that he's making his girlfriend a bouquet out of poison sumac. Then he starts scratching madly, which makes him swell up until he can't move. This, unfortunately, coincides with Robotnik making Pseudo Sonic, a robotic duplicate meant to infiltrate Knothole and discredit Sonic.
- Calvin and Hobbes: After Calvin utterly fails a report on plants, he angrily asks what good it does to identify plants while holding a branch. Hobbes then replies "I believe that's poison sumac you're holding." He also regularly runs afoul of poison ivy during family camping trips.
- Jason and Marcus get sent on a night hike through poison ivy as part of an Escalating War of pranks with the girls. They compound the folly by deciding to use the leaves as camouflage.
- Another strip has Jason and Marcus running through fields covered in poison ivy in an attempt to escape from Peter after they shot him in the face with superglue-covered suction darts. In this case Jason and Marcus did know their vines but decided it was better to deal with the poison ivy than be caught by Peter (who seems in the mood to re-enact The Shining).
- Calvin & Hobbes: The Series reuses one bit from Calvin and Hobbes above.
- This trope is a very big reason why, in the Discworld, the Assassins' Guild School has a Botany Department. It is run by a woman who became a late entrant to the Guild owing to her unparalleled knowledge and expertise concerning green growing things. In a later tale, her daughter exploits the fact a troublesome idiot does not know what a croton oil plant looks like, is not aware they should not be touched, and are in fact to be avoided, and therefore has no idea of the subsequent emetic and irritant effects.
- In the StarWars fic Encounter on Myrkr Luke Skywalker and Mara Jade try re-enacting their night on Myrkr after they’re married, while Talon Karrde is setting up a base there. They start making love in the brush and wind up contacting the stinging, itching, swelling plant from their first experience(see the Literature entry below)again. The medic says it’s the worst case he’s ever seen, over their entire bodies, and they’re forced to admit what happened. Han Solo remarks that he’d think they’d have learned their lesson about that plant the first time.
- One Saved by the Bell fanfic, "The One Gigantic Fix", riffed on by Rob Bricken here, uses poison ivy as the reason why Zack has a permanent erection and thus needs some Deus Sex Machina to save him. Maybe.
Now, it might had been the fact that he had covered himself with something that might possibly had been poison ivy or that there was something in the water. I really don't know.
- The Legend of Spyro: A New Dawn: After going awhile into the forest temple, Sparx begins getting an unpleasant rash. Ember identifies the plants in the bush he passed through as poison ivy, which she knows because her mother taught her about it (not because Dragons get poison ivy, which they don't, but because eating it is really dangerous).
- The Twilight / Marvel Universe fanfic Wolverine has Bella Logan (AKA "Wolverine") and her grandfather Victor Creed/Sabertooth reminiscing about an incident during their time with Weapon X, when they went camping with the rest of their team and one of them ran afoul of this trope.
Victor: "Remember when we ran outta toilet paper, and Wade went and used poison ivy to wipe?"Bella: "Oh, god, yes! I caught him using one of his swords to scratch." (snickers) "He went a whole day without talking to me. It was beautiful."
- Early in the movie Coraline, the title character brushes some leaves off a stick and uses it as a water rod. She meets Wybie and has a fairly long conversation with him, and at the end, he throws in that the stick she's holding is poison oak.
- When Sid's girlfriend leaves him in Ice Age: Collision Course, he asks if it was because he made her a bikini out of poison oak. He then absent-mindedly uses said bikini as a handkerchief, causing his nose and eyes to swell up.
- In Trolls, Poppy eats a berry that causes her to get spots all over her body and swell up into a ball.
- In one of The Baby-Sitters Club books where the sitters go to camp, Stacey finds "a comfortable patch of leaves" to sit in during the campfire on the first night. She spends most of the rest of the trip in the infirmary.
- In the Fancy Nancy book “Poison Ivy Expert”, Nancy thinks she knows what poison ivy looks like and can avoid it while gathering flowers for her teacher. She’s wrong and though the teacher is unharmed, she gets a nasty case.
- Galaxy of Fear: Tash climbs a tree to escape attention, then starts crawling her way through the treetops, well above the threat she's trying to avoid. Unfortunately, at some point, she crawls into the branches of a vesuvague tree, which snares her in its vines and threatens to strangle her.
- In Heir to the Empire, Mara Jade knows perfectly well what the leaves of a certain vine do to human skin, and brushes Luke's arm with the tip of one to prove how it will be a useful disguise element, much to his dismay. She takes great delight in how it hurts and then itches, and asks if he wants her to apply it or he'd rather do it himself. He'd rather do it himself. When Imperials find them, one asks what the hell happened to his face, and he grunts "Walked into a bush."
- Azusa in I've Been Killing Slimes for 300 Years and Maxed Out My Level has this as her first skill when she reincarnated as a witch with Complete Immortality. Through this skill, she is quite well-known in the nearby village as a herbalist, as her treatments are rather effective.
- In The Last Continent, Rincewind discovers a vine which, if you carefully peel off the bark, gives you a nasty rash. What he'd been trying to find was a vine which, if you carefully peel off the bark, gives you a serviceable twine. It took him several more rashes to achieve that part.
- The Poisonwood Bible by Barbara Kingsolver: at one point, an American missionary in Congo ends up with tree sap on his arm and forehead, but pays it no heed. A local tells him "That tree, it bites", a warning he can't make sense of. The next day, he wakes up with a severe skin irritation where the sap was.
- 1000 Ways to Die had a guy attempting to imitate the actions of survivalists on TV who records himself surviving on plants he found in the wild. Having no training, he's incapable of identifying the plants he eats as oleander, foxglove, and hemlock, all of which are highly toxic and lead to his death.
- The Closer: In "Lover's Leap", Brenda ignores Buzz's urgent attempts to tell her something while she is examining a crime scene. What he was trying to tell her was that she was standing in poison oak. This later becomes an important clue in revealing the killer.
- On ER, after Mark and Elizabeth return from a camping trip, she is seen scratching at her hands. A fellow doctor diagnoses her with poison ivy. When she asks if it will spread, he tells her it depends on what she last touched. Answer Cut to Mark scratching his nether regions.
- Fargo: In "The Heap", Ida mentions that when Vern was courting her, he gave her a bouquet of poison ivy. Which he picked himself.
- Stuart and Ann's camping misadventure on L.A. Law. Remember the TP next time.
- After a huge fight and emotional breakdown with an unrequited love interest in a forest, the title character of Malcolm in the Middle dries his tears with some leaves he found. The girl he is with tells him he's using poison oak. We see a rather disturbing shot of his face a little later, which resembles the character No-Face in Twisted Metal: Black.
- On My Name Is Earl, Earl meets up with an old friend, who is now living in an abandoned bookmobile in the woods. The man has been living off of berries that have been causing him to hallucinate, and to believe he's married to a beautiful woman named Irene. It turns out that "Irene" is a raccoon. Earl recalls, too, that Joy ate those same berries on a camping trip they took while they were still married, and she too, did the Mushroom Samba.
- In NCIS, while investigating a murder in a national park McGee has to search a patch of poison ivy for a murder weapon. Tony recognizes what the plant is, but decides not to tell him. To be fair, Tony had been telling McGee about searching in the outdoors, when McGee went off on him for treating him like a probie, and assures Tony that he learned plenty in Boy Scouts.
- A variation of this on Parks and Recreation. The character Jerry is initially introduced as the leader of pre-teen nature walks. He plucks a plant called country honeysuckle, which Leslie smells and takes a bite of. She quickly spits it out saying it's bitter, and Jerry tells her she shouldn't have eaten it: "the animals know you don't eat the country honeysuckle." Leslie's tongue swells and grows numb.
- In Salute Your Shorts, Ug and Z.Z. go on a nature hike when Ug comes across what he thinks is a rare plant, and asks Z.Z. to take his picture with it so he can get into a local shrub club. Z.Z., however, believes that the plant is actually poison sumac. She ends up being right.
- Yellowjackets: In "Bear Down" the girls are out foraging for food. One of the team members has some knowledge about what is safe.
- Homer & Jethro's "The Battle of Kookamonga":
Well we crept up to the water and we see the girls a-swimmin'
There musta been a hundred of them pretty young women
They looked so fine even birds forgot to sing
We lay down in the poison oak and didn't say a thing
- Just one of the many hazards of life in Camp Granada as described by Allan Sherman in Hello Muddah, Hello Fadduh (A Letter from Camp):
I went hiking with Joe Spivey
He developed poison ivy
- Wanderers.io: Mushrooms can be taken as food, but some kinds are poisonous and will reduce a minion's health by 1. However, the "Mycology" skill makes any mushroom edible.
- Unisys Icon game A Week in the Life of... had one of the characters on some hiking trip. The end of that character's storyline required the player to remember what poison ivy looked like from pictures shown a while ago, then required having him run through plants as a Timed Mission, where plants randomly appear. As an additional note, the game was based off CPU clock speed, thus the faster computers would be more difficult to play.
- On The Edge: In Hirofumi's episode Giant Hogweed, he is tending to a plant his girlfriend Chie gave him. To his surprise, it started growing at such a fast rate that he decided to trim it, only to get the sap on his left eye and hands, which swelled them up and caused him burning pain. When he got rushed into the hospital, the doctor tells him that the plant he tended to was the titular giant hogweed.
- Housepets!: A warning that part of the Milton estate is a protected area for endangered itching terror ivy comes a tad late for a sneaking Steward and Thomas.
- One Ozy and Millie strip has Millie declare herself a visionary unconcerned with mundane details, only for Ozy to point out she's standing in poison ivy.
- This xkcd comic is the Trope Namer. Ironically, the oxalate crystals in Virginia creeper can also cause an allergic reaction in some people.
- Adventures of Sonic the Hedgehog:
- Sonic randomly blunders into an entire valley full of "poison flowers" while saving a character from a completely different threat.
- One Sonic Sez segment was about how to identify poison ivy. Hilariously, the poisonous plant shown looked more like marijuana.
- Animaniacs: In "Sound of the Warners", after using the bathroom in a bush, Dr. Scratchansniff gets an awful itch, because he was in a poison oak bush.
- Avatar: The Last Airbender: In the second season, Iroh has a run-in with some of these. "Delectable tea?... Or deadly poison?" Needless to say, the plant in question is poisonous, causing him to break out in a rash. "When the swelling reaches my throat, I will stop breathing." And to show he hasn't learned his lesson, Iroh brings out some berries that may cure him or make him blind. Zuko insists they find a doctor instead. It's implied Iroh did this on purpose for that very reason, since before this incident Zuko was insisting they avoid contact with any people whatsoever.
- The Day My Butt Went Psycho!: In "Snoozing Booty", Zack is trying to trick Eleanor into kissing Deuce (It Makes Sense in Context), so he holds some mistletoe over him and claims it's the law that she has to kiss him. She points out that that is not an actual law, and that what he is actually holding isn't mistletoe but poison ivy. As Zack runs around screaming, Eleanor then hands him the poison ivy vine to scratch himself with.
- Family Guy: In "Bigfat", when Peter, Quagmire, and Joe were lost in a forest after Peter crashed the plane that Quagmire was piloting, Peter eats some berries that cause his lips and the skin around his eyes to recede.
Peter: Okay, these are a 'Maybe'.
- Hey Arnold!: A camping episode ends with Big Bob Pataki rushing through a small bush blocking the path (after interrupting Arnold that they have to go around it) to get back to his campsite after a disastrous hike. This bush, of course, was poison ivy, causing him more misery.
- Kick Buttowski: Kick and Brad are lost in the woods. While Kick, who likes to rough it, sleeps on the bare ground, Brad brags about how Kick wished he had a comfy blanket of natural foliage like him. "You're right, Brad. I wished I had a blanket of poison ivy."
- My Little Pony: Friendship Is Magic: In "Bridle Gossip", the Mane Six walk through a patch of bright blue flowers to stop Apple Bloom following Zecora. The next morning they wake with embarrassing changes, such as Pinkie having a swollen tongue and Applejack being shrunk to miniature size, all of which they blame on a curse cast by Zecora. It's eventually revealed that the flowers were from a magical plant called "poison joke", and the girls' ailments were a side effect of the plant.
- Pac-Man: In "Backpackin' Packy", Pac-Man was giving the scouts a plant identification lesson when he picked up a leaf that he learned too late would give him a severe itch.
- The Simpsons: In "Margical History Tour", Lisa as Sacajawea is giving Lewis and Clark's expedition party quick advice and tells one soldier that he's holding poison oak.
- SpongeBob SquarePants: When SpongeBob and Patrick get lost in a forest on a road trip, SpongeBob looks for food and finds a type of berry which causes him to instantly swell up and turn purple. He doesn't need an antidote, as he can just pop himself like a balloon with a pin and regenerate.
- Stōked: Reef picks wildflowers for Finn and leaves them on her bed. Unfortunately, there is poison ivy mixed in with the flowers.
- Total Drama:
- "Not So Happy Campers: Part 2": Katie and Sadie unknowingly squat in poison ivy to pee. They realize their error when their butts start itching like mad and Bridgette deduces what the cause of it is.
- "No Pain, No Game": Izzy nominates herself to undergo a poison ivy spa treatment for 10 seconds. She voluntarily keeps it on a little longer and when the wraps are removed her face is all swollen and red. It doesn't stop her from laughing.
- "Eat, Puke and Be Wary": Zoey makes a living salad for the cooking contest. It stands a chance to win, so Scott sabotages her dish by mixing poison ivy leaves into it. When Zoey eats from her salad, her mouth and throat become itchy to the point where it makes her vomit.
- We Bare Bears: In "Lord of the Poppies", Grizz, left in charge of the Poppy Rangers, misidentifies some berries as edible. Cut to one of the Rangers throwing up.
- The Wild Thornberrys: Nigel starts to get real itchy from what is believed to be poisonous plants, but he is immune to them because he rubbed some of them all over his body. It turns out that it was chickenpox, which he missed as a kid.
- As a rule of thumb, no non-toxic plant exists which is completely indistinguishable from a poisonous equivalent. But there are plenty of plants belonging to the same or similar families which, to an untrained eye, look similar enough that falsely identifying them can become a problem. If, when foraging, you are unable to identify a plant with complete certainty, it is best to leave it alone.
- This is the main hazard posed by "Stalin's revenge", also known as the giant hogweed. It's an umbellifer taller than most sapling trees (apparently can reach 5,5 meters - that's over 18 feet). The poisonous sap/juice of this plant causes burns comparable to mustard gas. And it makes the skin sensitive to sunlight. It's also basically the Eastern European equivalent of kudzu, an imported plant that the authorities considered potentially useful but it really wasn't and it spread uncontrollably all over the land. The worst part? It looks harmless, even beautiful, if you don't know better, as many city kids learn to their chagrin after a trip to the country. Its leaves are also broad, large, and inviting as impromptu toilet paper. Many a City Slicker temporarily lost the ability to sit painlessly because of this plant.
- Unlucky people can get the same reaction from mango peels as others do from poison ivy, because mangos and raw cashews contain a chemical similar to urushiol (the ingredient in poison ivy that causes the rash).