Anemarrhena: A plant genus of the family LILIACEAE. Members contain anemarans (POLYSACCHARIDES), hinokiresinol, mangiferin (a xanthone), and timosaponin (a steroidal saponin).Rhizome: Root-like underground horizontal stem of plants that produces shoots above and roots below. Distinguished from true roots which don't have buds and nodes. Similar to true roots in being underground and thickened by storage deposits.Pharmacognosy: The science of drugs prepared from natural-sources including preparations from PLANTS, animals, and other organisms as well as MINERALS and other substances included in MATERIA MEDICA. The therapeutic usage of plants is PHYTOTHERAPY.Spirostans: Cholestane derivatives containing a fused lactone ring at the 16,17-position and a spiroglycosidic linkage at C-22. Members include sarsaponin, DIOSGENIN and yamogenin.