Shen Collection, Upper Volume Radical: Grass (cǎo) Kangxi Strokes: 14 Page 1041, Entry 07 Pronounced ping. In the Jade Compendium (Yupian), it refers to duckweed. According to the commentary in the Materia Medica (Bencao Zhu), duckweed is formed from the transformation of poplar catkins. A single leaf will produce several more overnight, and underneath the leaf are fine filaments, which are its roots. Book of Rites (Liji), Monthly Ordinances (Yueling): Duckweed begins to grow. Rites of Zhou (Zhouli), Notes on the Master of Duckweed (Pingshi zhu): Duckweed is a grass that has no roots and floats on the surface of the water; it is named this because it does not sink. Book of the Later Han (Hou Hanshu), Biography of Zheng: Drifting north and south like floating duckweed. There is also the Green Duckweed (Qingping), which is the name of a sword. It is also used in place names. Bamboo Annals (Zhushu Jinian): Hunted at Ping Marsh. Book of Jin (Jinshu), Treatise on Geography: Pingxiang, which belongs to Ancheng Commandery. Also, the Collected Rhymes (Jiyun) and Orthography of Rhymes (Zhengyun) state that it is the same as the word for apple (ping). The Collection of Rhymes (Yunhui) states that the two words were originally the same thing, written differently but identical in sound and meaning. Regarding the line in the Classic of Poetry (Shijing), Eating the wild apple, the Mao commentary explains that it is duckweed. The Zheng annotation explains that it is mugwort. The sub-commentary explains that duckweed is a water grass and not something deer eat. Therefore, Zheng does not follow the Mao interpretation. Looking at the subsequent lines regarding eating wormwood and scallions, which are land grasses, one can see that apple (ping) should be interpreted according to the sub-commentary as mugwort, while duckweed is a water plant, and they are entirely two different things. While the characters may be used interchangeably, their meanings do not correspond, and the assertion in the Collection of Rhymes (Yunhui) is incorrect.