Shen Collection, Upper Volume Radical: Grass (cǎo) Xu Kangxi strokes: 21 Page 1065, Entry 25 Tang Rhyme (Tangyun): Pronounced xu. Explaining Graphs and Analyzing Characters (Shuowen): Water plantain. Approaching Elegance (Erya), Explanation of Grasses: Xu is known as cow lip. Book of Odes (Shijing), Wei Wind: At that bend of the Fen river, I go to gather the xu. Commentary (Shu): It is what is known today as water plantain. Also, in Materia Medica (Bencao): Xuduan, a name of a medicinal herb.