The Collaborative International Dictionary of English v.0.48:

Leontopodium \Leontopodium\ n.
   A genus of plants including the edelweiss (Leontopodium
   alpinum).

   Syn: genus Leontopodium.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Edelweiss \E"del*weiss\, n. [G., fr. edel noble + weiss white.]
   (Bot.)
   A little, perennial, white, woolly plant (Leontopodium
   alpinum), growing at high elevations in the Alps. It is the
   national flower of Austria.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

Leontopodium alpinum
    n 1: alpine perennial plant native to Europe having leaves
         covered with whitish down and small flower heads held in
         stars of glistening whitish bracts [syn: edelweiss,
         Leontopodium alpinum]