The objective of this article is to analyze the function of the images of terrible plants in John Wyndham’s novel The Day of the Triffids. To this end, plant teratology allows us to elucidate the narrative configuration of the fantastic in the chaos that the novel makes explicit, the fears that arise after World War II and the political orders that are established after the threat of extinction. Consequently, this article investigates how plant thought has been omitted in the narrative structure in favor of a plant terror. The article is divided into three parts. The first part is a study on the two positions of vegetal thought to elucidate how the novel omits vegetal semantics to build a horror narrative. The second part proposes that the vegetal terror structures the idea of chaos in the novel. The third part interprets the affirmation of human existence from the control of vegetal agency. In conclusion, Wyndham’s novel will make explicit that the configuration of civilization necessarily requires the establishment of an order between species: an order in which the human being is established as the governing agent of dynamics and existence.