Book excerpt: The First Symposium on Use of Plants for Toxicity Assessment was held in Atlanta, Georgia, on April 19-20, 1989. This publication contains 29 refereed papers divided into six groups: Regulatory Perspectives, Comparative Toxicology, Plants and Xenobiotic Uptake, Plants and Air Pollution, General Phytotoxicology, and New Approaches. The 2nd Symposium on Use of Plants for Toxicity Assessment was held in San Francisco, California, on April 23-24, 1990. This publication contains 35 refereed papers divided into six groups: Regulatory Perspectives, Applications of Plant Bioassays/Photosynthesis, Xenobiotic Uptake by Plants, General Phytotoxicology, Biochemical and Genetic Applications, and New Approaches.