Chang Rong was the daughter of the Prince of Shang, and practiced Daoism on Changshan, eating penglei stems for more than two hundred years, but appearing little over twenty. Skilled in finding zicao, she would sell it to dyers, obtaining money to give to the poor and unwell, coming and going to towns and cities, where she was seen by generation after generation. Among people near and far, those who served her numbered over a thousand, but it was never understood how she cultivated the Way. She often travelled in the day, but her shadow could not be seen. Some said: “Chang Rong is one who can exercise asceticism.” She suddenly ascended to the heavens and departed.
From the Nüxianzhuan.
Li Fang 李昉, et al., Taiping guangji 太平廣記 (Extensive Gleanings from the Era of Great Harmony), 10 vols (Beijing: Zhonghua shuju, 1961), ii, 59.362:
 This zicao 紫草 seems to be Lithospermum erythrorhizon (purple or red gromwell, etc.). See https://en.wikipedia.org/wiki/Lithospermum_erythrorhizon.