The Collaborative International Dictionary of English v.0.48:

Luteolin \Lu"te*o*lin\, n. [From NL. Reseda luteola, fr. L.
   luteolus yellowish, fr. luteus: cf. F. lut['e]oline. See
   Luteous.] (Chem.)
   A yellow dyestuff obtained from the foliage of the dyer's
   broom (Reseda luteola).
   [1913 Webster]