Shen Collection, Upper Volume Radical: Grass (cǎo) 蕬 Kangxi strokes: 18 Page 1059, Entry 08 Collected Rhymes (Jiyun): Pronounced si, sound si. Classified Chapters (Leipian): Tu-si, a medicinal herb. Originally written as si. Also, citing Proper Character Mastery (Zhengzitong) which references Jade Hall Idle Talk (Yutang Xianhua): Si grass is a water plant from the Jiangnan region with leaves like those of a scallion, growing according to the depth of the water.