G'Quan Eth: plant indigenous to the Narn homeworld, used as incense in religious ceremonies from Babylon 5 TV series. It is ritually burned as incense, and its seeds are a narcotic for Centauri when dropped in alcohol. The G'Quan Eth plant is "difficult to grow, expensive to transport, very expensive to own." Whether it affects other species in this way when in alcohol is not clear, but we know that Narn don't seem to use it as a recreational drug (Londo chides G'Kar for Narns "It's a shame you Narns waste them, burning them as incense") and that it is illegal to possess on B5 except in religious contexts. The plant is presumably named after Narn spiritual leader G'Quan.
Snake vine: an odd-looking vine with dusky, variegated leaves hunkered around a stem that winds a stranglehold around nearby trees, eventually killing them from the Sword of Truth fantasy series by Terry Goodkind. It will bite at nearby creatures, leaving deadly toothlike thorns that burrow into their skin and eventually kill them. There is actually a plant commonly called by this name that is native to Australia. See Snake vine
Tesla trees: large electrified trees from the planet Hyperion in Hyperion Cantos novels by Dan Simmons. They appear to store up electricity inside their body during certain seasons, releasing all of it in huge arcs of lightning from their crown, burning away all that was growing or walking near them and thus getting fertilizer.
Athelas: a healing plant with long leaves (also known as Kingsfoil or Asëa Aranion).
Ents: an ancient walking, talking tree-like race led by Treebeard (also known as Fanghorn). According to Tolkien these shepherds of the forest, were the oldest mortal race in middle earth. They were on the verge of extinction by turning into trees, due to the long ago disappearance of the Entwives: the female version of Ents. Their name is derived from the Anglo-Saxon word for giant. Ents we are told are not trees, but it is not clear if they were plants or animals or something in-between.
Mandrakes: tubers that look like babies when young. Their screams can kill when fully grown. A potion made from mature mandrakes can restore victims that have been petrified. A different kind of mandrake is a real plant. Whilst the mandrake as it appears in the books and films is fictional, Rowling's description does reflect genuinely held beliefs about the mandrake, in particular, the danger surrounding its screams. This led to the practice of using dogs to collect the mandrake, and the blocking of ears during collecting.
The Turkish little rude plant: A remarkably smutty piece of flora used by the Turks.
Walking tree of Dahomey (Quercus nicholas parsonus): the legendary walking tree that can achieve speeds of up to 50 miles an hour, especially when it is in a hurry. There is movie footage from the late 1940s in which a walking tree actually sprints after a cheetah. Very funny, although the cheetah was subsequently quite rooted.
In the 2009 film Avatar
Plants in Pandora have evolved according to the characteristics of their environment, which has an atmosphere that is thicker than on Earth, with higher concentrations of carbon dioxide, xenon and hydrogen sulfide. Gravity is weaker in Pandora, thereby giving rise to gigantism. There is a strong magnetic field, causing plants to develop 'magnetotropism'. A particularly intriguing quality of flora and fauna in Pandora is their ability to communicate with each other. This is explained in the movie as a phenomenon called 'signal transduction', pertaining to how plants perceive a signal and respond to it.
In DC Comics
The Black Mercy is an extraterrestrial hallucinogenic plant used a weapon by the supervillain Mongul. Mongul first uses it in "For the Man Who Has Everything", a story by Alan Moore and Dave Gibbons that was first published in SupermanAnnual #11 (1985) and later adapted into the Justice League Unlimitedepisode of the same name and for one episode of "Supergirl" called "For the Girl Who Has Everything", where in that episode the plant was sent by Kryptonian Non (comics). Described in the original story by Mongul as "something between a plant and an intelligent fungus", the Black Mercy attaches itself to its victims in a form of symbiosis, and feeds from the victim's "bio-aura". The organism is telepathic, and reads its victim's heart's desire, giving them a logical simulation and an ending that the victim wants, which the victim experiences an entirely immersive, virtual experience in which their actual surroundings are masked to them. According to Mongul, victims are capable of "shrugging off" the hallucination, though some find the experience too compelling too do so unaided.
The Black Mercy is typically depicted as consisting of dark green, thorned vines that attach themselves to a humanoid victim's upper torso, with a set of pink flowers, each with a long, red, tentacle-like stigma, growing in the center of the victim's chest. When Mongul first uses the Black Mercy on Superman, they burrow through his costume and into his body, able to penetrate his otherwise invulnerable skin because, Wonder Woman senses, they are at least partially magical, which is one of Superman's weaknesses. During his experience with the organism, Superman's breathing appears faint, and his ability to sense the fraudulent nature of the simulation it feeds him and fight it manifests itself as tears produced by his actual eyes. The Black Mercy can pulled off a victim by a strong humanoid such as Batman, and Mongul uses special protective gauntlets to handle the plant safely. Superman is not able to awaken from the Black Mercy's simulation without help from Batman, though Oliver Queen and Hal Jordan are both able to do so in a subsequent storyline.
In the video game, Injustice 2 Supergirl mentions Black Mercy in pre-battle dialogue with Scarecrow. She states dealing with him is no different than dealing with Black Mercy, causing Scarecrow to ask her what is Black Mercy out of curiosity, causing Supergirl to describe it as an evil space plant.
Characters who have experienced the Black Mercy include:
Superman sees himself on a still-intact Krypton with his biological parents, married to a retired actress named Lyla, and a son named Van.
Batman envisions a life in which his parents were not murdered during his childhood, and he is married to Kathy Kane.
Mongul envisions a life in which he successfully kills Superman, before setting out across the universe, killing all of his enemies, entire populations kneeling before him amid his destruction of countless galaxies.
Green Arrow envisions a life in which he is married to Sandra "Moonday" Hawke, and in addition to their older son Connor, they have a younger son, and a newborn third. When Mongul uses the Black Mercy on him, Green Arrow was caught along with Hal Jordan, with the result that he saw what Hal believed would be his perfect life.
Hal Jordan envisions a life in which his parents and his siblings are present in his life, and Sinestro is a friend who fights by his side as a member of the Green Lantern Corps. When Mongul uses the Black Mercy on him, Jordan was caught in the same illusion as Oliver Queen, which resulted in Jordan creating what he believed would be Queen's perfect life rather than Queen experiencing his own idea of a perfect life, allowing Queen to see through its simulation and thus awaken from it.
Man-eating tree or Madagascar tree: a fictitious tree in the forests of Madagascar. There are stories of similar trees in the jungles of Mindanao Island in the Philippines. The tree is said to have a gray trunk and animated vine-like stems used to capture and kill humans and other large animals. Comparable plants are mentioned in tall tales and fiction.