Concentrations of secondary metabolites in the foliage of trees with and without chestnut blight. From five field plots of chestnut trees, concentrations of terpenes (A) phenolics (B) and tannins (C) in ungalled leaves, galled leaves, and galls of trees with (DK + CP) and without (DK) infection by Cryphonectria parasitica. Figures show means ± SE of trees in each treatment group (square root transformed data).