Impact of herbicides on physiology and ecology of hydrophytes A Pharmacognostical Study on Herba Spirodelae and Its Adulterants Determination of nine kinds of nucleosides in Spirodelae Herba from different habitats by UPLC-MS/MS The Sensitivity of Chloroplast Ultrastructure of Two Duckweed Species to Simulated Acid Rain Studies on the Chemical Constituents of Common Ducksmeat (Spirodela polyrrhiza) Effects of Cerous on the Cu-resistance of Spirodela polyrhiza