spartium scoparium

from The Collaborative International Dictionary of English v.0.48

Sparteine \Spar"te*ine\, n. (Chem.)
   A narcotic alkaloid extracted from the tops of the common
   broom ({Cytisus scoparius}, formerly {Spartium scoparium}),
   as a colorless oily liquid of aniline-like odor and very
   bitter taste.
   [1913 Webster]