Source : Webster's Revised Unabridged Dictionary (1913)

Clematis \Clem"a*tis\, n. [NL., fr. Gr. ? brushwood, also (from
   its long, lithe branches) clematis. fr. ? twig, shoot, fr. ?
   to break off.] (Bot.)
   A genus of flowering plants, of many species, mostly
   climbers, having feathery styles, which greatly enlarge in
   the fruit; -- called also {virgin's bower}.

Source : WordNet®

clematis
     n : any of various ornamental climbing plants of the genus
         Clematis usually having showy flowers