The Surata IV Vine was a semi-intelligent predatory plant that lived on the surface of the planet Surata IV featured on the Star Trek: The Next Generation episode Shades of Grey.
Able to seek out warm blooded beings, the vine had a series of thorns on it which it would use to strike its victims. The thorns were covered with microbes that would paralyze the victim's nervous system and soon kill the victim once the brain was reached. It was able to kill most of the animal life forms in the area, all of which died nearby. As the animals decayed and fossilized their nutrients would enrich the soil for the vine to feed off of. The vine was several thousand years old by the mid 24th century.
In 2365 the USS Enterprise (NCC-1701-D) visited Surata IV and conducted a survey of the planet. When Wiliam Riker approached the vine saw its chance and stung Riker, infecting him with microbes. Beamed back to the ship Dr. Pulaski began treatment on Riker.
Commanders Data and Geordi LaForge were sent back to the surface, where they found the vine plus the various animal fossils nearby. Data was able to keep the vine from infecting LaForge, and found the thorn used to sting Commander Riker. Cutting the thorn loose they were able to beam away before the vine could take retaliate.
Riker nearly died from the microbe infection, but Pulaski was able to devise a treatment. Provoking certain memories she was able to cause neurological energy patterns in Riker that were lethal to the microbes, eradicating the microbes within him.