The Collaborative International Dictionary of English v.0.48:

Gelsemium \Gel*se"mium\, n. [NL., fr. It. gelsomino jasmine.]
   1. (Bot.) A genus of climbing plants. The yellow (false)
      jasmine (Gelsemium sempervirens) is a native of the
      Southern United States. It has showy and deliciously
      fragrant flowers.
      [1913 Webster]

   2. (Med.) The root of the yellow jasmine, used in malarial
      fevers, etc.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Gelsemium
    n 1: evergreen twining shrubs of Americas and southeastern Asia
         [syn: Gelsemium, genus Gelsemium]