Tripterygium hypoglaucum

Tripterygium regelii, or Regel's threewingnut (Pinyin: Dongbei Leigongteng), is a rambling, shrubby perennial deciduous yellow vine native to Korea, Japan and Manchuria. It grows to about 200 centimetres (79 in). Small very pretty yellowish white or white flowers appear in May–June and are produced on 203–229 millimetres (8.0–9.0 in). long panicles, and smell somewhat of new-mown hay. Fruits are greenish white, 3-angled, and winged. Certain extracts from Tripterygium wilfordii, as well as from Tripterygium hypoglaucum (now considered identical to T. regelii) and Tripterygium regelii, were discovered in the 1980s to have temporary antifertility effects, which has led to research on its potential as a contraceptive. Tripterygium regelii is listed as a poisonous plant in the U.S. Food and Drug Administration Poisonous Plant Database.