Human cognition is influenced by natural selection which results in better information retention related to survival and faster visual recognition of potential threat. Plants are excellent models for studying human preferences because of the long evolutionary connectedness of humans with plants as food sources, although research in this field is scarce. We created visual detection tasks to investigate human responses to toxic and non-toxic plants using a sample of children (N = 80) and adolescents (N = 80). As predicted, toxic plants were detected significantly sooner than non-toxic plants. Children showed faster plant detection times than adolescents and females were faster in identification of plants than males. There were, however, no differences in toxic plant identification skills with respect to age and gender. These results suggest that plant toxicity, as an example of survival-relevant information, meets with increased attention on the part of humans and needs to be incorporated into teaching botany.