Key application: For relief of low back pain; symptomatic relief of mild osteoarthritic and rheumatic complaints. (ESCOP.) The bark contains salicin 0.23%, salicase and tannin (6-12%).The phenol glycosides reported from the plant include fragilin, glycosmin, grandidentatin, picein, populin, sali- cin, salireposide, salicyloyl tremuloi- din, triandrin and tremuloidin.Willow bark consists of the dried bark or twigs of various species of the genus Salix, including S. purpurea L. and S. daphnoides Vill.Salicylate concentrations vary greatly among Salix sp. Salix alba bark is reported to contain 0.49-0.98% salicin; Salix purpurea bark 3-9%, Salix daphnoides bark 4.9-5.6% and Salix fragilis bark 3.9-10.2%. (Natural Medicines Comprehensive Database, 2007.)... salix fragilis