イラクサ科カラムシ属の多年草で、学名は Boehmeria longispica (syn. Boehmeria japonica var. longispica)。英名はありません。
The "Yabu-mao" (Boehmeria longispica) belongs to Urticaceae (the Nettle family). It is a perennial herb that is native to Japan, as well as Taiwan, the Korean Peninsula and China. This herb grows in woodlands and stream banks, and it can reach up to 1 m in height. The leaves are ovate-round and opposite with toothed edges. They are covered with hairs. The string-like clusters are borne on the axils from July to October. It is monoecious. The female clusters are at upper stem and the male clusters at lower. In Taiwanese Chinese, it is called "長穗苧麻" and in Chinese "野綫麻" (ye xian ma).