gelsemium

< /dʒɛlˈsi mi ə/.

1. the dried rhizome and root of yellow jasmine, formerly used as a sedative in the form of a powder, tincture, or fluid extract.

noun plural -miums or -mia (-mɪə)

1. any climbing shrub of the loganiaceous genus Gelsemium, of SE Asia and North America, esp the yellow jasmine, having fragrant yellow flowers
2. the powdered root of the yellow jasmine, formerly used as a sedative