葎草（学名：Humulus japonicus），又称拉拉秧、拉拉藤、五爪龙，多年生茎蔓草本植物。株长1～5米，雌雄异株，通常群生，茎和叶柄上有细倒钩，叶片呈掌状，茎喜缠绕其它植物生长。此植物耐寒，抗旱，喜肥、喜光。3、4月间出苗，雄株7月中、下旬开花，花序圆锥状，花被5，绿色。雌株8月上、中旬开花，花序为穗状。9月中、下旬成熟。中国除**、青海、**外，其他各省区均有分布；俄罗斯、朝鲜、日本也有分布。嫩茎和叶可做食草动物饲料。

Humulus japonicus (Japanese hop, synonym H. scandens) is an ornamental plant in the Cannabaceae family. Originally found in temperate parts of Asia (China, Japan, Korea, ****** and Russia) and the tropical environment of Vietnam, Humulus japonicus was imported to the North America in the 1800s for use in an Asian tonic and as an ornamental plant. Since its arrival in North America, Japanese hop has been very successful in spreading in North America. It has a wide distribution and can be found throughout the Northeastern U.S. and eastern Canada. It is considered an invasive species in North America. The composition and chemistry of the oils found in Humulus japonicus differs from its relative the common hop, Humulus lupulus. As a result, the Japanese hop is not used in the production of beer.