Poison Ivy's Plants are venomous plants in Batman: Arkham Asylum. They are capable of killing people directly with their vines, or indirectly by sending out poisonous spores.
Before Arkham Asylum Incident
Poison Ivy created plant pods that release deadly spores that seek out anything that moves like guided projectiles. She uses these to attack Gotham City, before Batman manages to stop her and sends her back to Arkham Asylum.
Arkham Asylum Incident
Following Ivy getting an injection of Titan, its effects work differently on her: instead of her body mutating into a giant form, Ivy's Plants grow rapidly. Multiple vines burst out of the ground on Arkham East, warpping around the Clock Tower. Another burst from the stairs by the Botanical Gardens.
As the night goes on, Ivy forces her plants through Arkham Island, and takes it over bit by bit. Anyone stupid enough to get close to Ivy's Plants is killed by venus-flytraps attached to the vines, which swallow their heads or bite off their limbs. Some even break into the Intensive Treatment Center's exit to the Utility Corridor while the Blackgate Prisoners enter. The Joker warns that prolonged exposure would shut down a person's nervous system.
Eventually, Ivy gained control of the entire island and uses spores that make it glow red. Batman goes back to the Botanical Gardens, which is filled with Ivy's Plants. Ivy attempts to use a giant flower to attack him, but Batman damages it and causes the plant to fall into a hole, along with Ivy. With Ivy out-cold, all of the plants on the island wither and die.
Arkham City IncidentSome plants can be seen growing in Ivy's old shop, Baudelair, which end up killing two thugs from Two-Face's Gang.
Ivy resides in a hotel wrapped in vines to keep out intruders. Catwoman breaks in and Ivy attempts to use her plant spores to kill her. Ivy also keeps her brainwashed henchmen inside flytrap-like plants until she needs them.