Comparative Analysis on the Metabolic Compositions of Flower Bud and Rachis of Tussilago farfara Based on GC-MS Fingerprinting Approach Monitoring of Chemical Components Changes during Tussilago farfara L. Development using NMR-based Metabolomics Observation on the Process of Flower Bud Differentiation in Medicinal Plant Tussilago farfara L. Flavonoids and phenolic acid derivatives from Flos Farfarae Embryology of Tussilago farfara (Asteraceae:Senecioneae) Phytochemical and pharmacological research progress in Tussilago farfara. Studies of the Spasm-relieving Effect of Glycyrrhiza uralensis Fisch.—Aster tataricus L. F. Puivis Mixture on Trachea in Guinea Pigs