Heterotelergones

Heterotelergones (also known as allelochemics) are a class of biologically synthesised chemicals (includes pheromones, venom, and phytoncides) which entice, repel, immobilize, or alter tissues.

Commonly used by terrestrial plants as a form of defence against insect herbivores, and by aquatic plants as a form of defence against algaeFact|date=February 2007.