phytotoxin

A phytotoxin is a chemical compound that is poisonous to plants. These substances can be produced by various organisms, including plants themselves, and play roles in ecological interactions such as defense or competition. The study of plant poisons is known as phytotoxicology.123

Phytotoxins can be classified based on their toxic effects, such as being poisonous to eat, poisonous upon contact, causing photosensitization, or producing airborne allergies. They encompass a wide range of chemical structures, including alkaloids, glycosides, and toxalbumins. While some phytotoxins are harmful, others may serve vital functions in the source organism's life processes.24