Renwu (壬午) and Guiwei (癸未) Yangliumu (杨柳木) refer to the wood that dies in Wu (午) and is buried in Wei (未). Even though it receives nourishment from the water of the Heavenly Stems Ren (壬) and Gui (癸), it remains ultimately weak and soft. Therefore, it is called Yangliumu (杨柳木), or Willow Wood.