Shen Collection, Upper Volume
Radical: Grass (cǎo)
Entry: Ao
Kangxi stroke count: 10
Page 1021, Entry 09
Jade Chapters (Yupian): Pronounced ao (rising tone).
Tang Rhymes (Tangyun): Pronounced ao (rising tone), sound is the same as ao.
Explanation of Graphs and Analysis of Characters (Shuowen Jiezi) records: Ku-ao is a type of grass. It has a bitter taste, and people in the Jiangnan region consume it to regulate qi.
Additionally, in Collected Rhymes (Jiyun): Pronounced yao (falling tone), sound is the same as yao.
In Approaches to Etymology (Erya), section on interpreting grasses, it is referred to as Gou-ao.
The Commentary (Shu) explains that it belongs to the thistle family; one type is called gou, the other is called ao.
Guo's Annotations (Guo zhu): It is about the size of a thumb and hollow in the center; the top of the stalk has moss-like parts, and it can be eaten when it has just begun to grow.
Also pronounced ao (falling tone). The meaning is the same.