Chen Collection, Middle Volume Radical: Tree (mù) Entry: Su Kangxi stroke count: 15 Page 550, Entry 05 Tang Rhyme dictionary: Pronounced su. Collected Rhymes (Jiyun), Rhyme Meetings (Yunhui), and Orthodox Rhymes (Zhengyun): Pronounced su. Explaining Graphs and Analyzing Characters (Shuowen Jiezi): Pu-su refers to a small tree. Book of Odes (Shijing), Shao Nan section: The woods have pu-su. Additionally, in the Er Ya (Erya), Explaining Trees: Su-pu is called heart-wood. Guo Pu commentary: Heart-wood is another name for hu-su. Sub-commentary: The hu-su has a heart that can become damp; in the regions along the Yangtze and Yellow Rivers, it is used to make pillars.