The Asiatic dayflower (Commelina communis) belongs to Commelinaceae (the Spiderwort family). It is a perennial herb that is native to Japan, as well as Taiwan, the Korean Peninsula, southern China and India. This her grows in roadsides or grasslands, and can reach 30-50 cm in height. The stems crawl on the grounds, and they are much branched and take roots at the nodes. The bright flowers bloom from June to September, and they last one day. The corolla consists of two large blue petals and one small white petal. The dye of petals has been used as a rough sketch for Nishijin weaving. It is called "鴨跖草" in Taiwanese Chinese and "鴨跖草" (ya zhi cao) in Chinese.