Vincetoxicum auriculatumVincetoxicum auriculatum, synonym Cynanchum auriculatum, is a species of climbing vine. Its Chinese name is niu pi xiao . V. auriculatum flowers between June and August; fruiting from August all the way to December.Distribution and habitatVincetoxicum auriculatum is native to Asian temperate and tropical regions; found in China, Bhutan, Nepal, and the northern parts of Pakistan and India. Its habitat is mountainous shrubland terrain, at elevations from 2800 to 3600 meters.StudiesEthanol extracts derived from roots of V. auriculatum are being studied for use in anti-cancer medicine; one preliminary study found extracts to have some cytotoxic effects on certain human tumor cell lines. The tests were conducted, both in vitro and in vivo, on both human subjects, and mice.