This important new edition commences with an overview of the biochemistry, physiology, functions and utilisation of plant secondary metabolites, followed by detailed surveys of alkaloids and betalains, cyanogenic glycosides, glucosinolates and non–protein amino acids, phenyl propanoids and related compounds, and terpenoids (monoterpenes, sesquiterpenes, sterols, cardiac glycosides and steroid saponins). A chapter is also included covering the importance of secondary metabolites in taxonomy, as viewed from the perspective of moecular systematics.