Painting of kucao (bitter herb) in the meticulous (gongbi) style, in colour on silk, from Bencao tupu (Illustrated Herbal). The painted illustrations in Bencao tupu were jointly executed by Zhou Hu and Zhou Xi in 1644 (the final year of the Ming period). The explanatory texts were provided by Zhou Rongqi. The book was not completed: each volume was to have contained 14-15 paintings, but only 29 are extant. Zhou Rongqi writes: Kucao is also known as jieduzi (poison-remover). It grows in Rongzhou [Yibin, Sichuan]. It is a climbing vine with thick, stiff non-deciduous leaves. The root is yellowish white with a coarse rind. The root is used in medicine.It is bitter in sapor, cold in thermostatic character, and non-poisonous. It has the properties of clearing heat and dispelling poisons; subduing fire and resolving phlegm; alleviating swelling of the throat and legs. It is used to treat wounds, lesions and toxic swellings (zhongdu); blockage disease (bi) and sore and inflamed throat; red, inflamed and painful eyes.