In John Wyndham's dystopian novel The Day of the Triffids, the mobile carnivorous plants are called triffids.
Triffids are tall, poisonous plants capable of moving, attacking humans with a lethal sting, and being cultivated for valuable oil. They become especially dangerous after a global event leaves most of humanity blind. The novel's tension comes from the collision of biological threat, social breakdown, and the struggle to rebuild organized communities.
The triffids are not the cause of the mass blindness. The blindness follows a spectacular worldwide meteor display, after which sighted survivors must cope with both the new disability crisis and the expanding plant menace. This distinction is a frequent source of confusion when the novel is summarized.
Wyndham's book was first published in 1951. It combines science fiction, disaster fiction, and post-apocalyptic themes, and it remains one of the best-known British novels about a society collapsing after a global catastrophe.