What are the historical allusions about rue?

After the death of Liu Bei in the first year of the establishment of Shu in the Three Kingdoms, Zhu Bao and Meng Huo, the prefects of Xianxu County, rebelled. In the third year after the founding of Shu, Zhuge Liang led his army on a southern expedition to Xianggao County (now in Anshun and Liuzhi, Guizhou Province). At that time, the weather was very hot and there was miasma. The Shu army was unbearably hungry and thirsty. The men and horses were exhausted. Suddenly they saw spring water. They were overjoyed and the men and horses drank from it.

Unexpectedly, symptoms of poisoning appeared immediately, and the lives of all the soldiers were in danger. Kong Ming was also helpless. In desperation, he went to the temple of Ma Yuan, the general of Fubo of the Han Dynasty, and knelt down. He was guided by the master "Wan'an Hermit" Meng Jie. It was then discovered that the water the soldiers drank was called Yaquan, and they had to use the Anle Spring water to detoxify the poison, and collect the "leaf and rue" to contain it. "Everyone has a leaf in his mouth, and the miasma will not invade." Then there was a great victory in capturing Meng Huo five times.