The Mysore thorn (Caesalpinia decapetala var. japonica) belongs to the family Caesalpiniaceae. It is a deciduos shrub that is distributed westward from Tohoku district of Honshu to Shikoku, Kyushu in Janan, as well as Taiwan, the Korean Peninsula and Cnina. This shrub grows in outskirts of woods or stream banks. The stem is viny and has many hooked spines. The leaves are bipari-pinnately compound. Bright yellow flowers with distinct red stamens come on the 20-30 cm long racemes from Arpil to June. The fruits ripen brown in fall and they are toxic. In Taiwanese Chinese, it is called "雲實" and "雲實" (yun shi) in Chinese.