The Collaborative International Dictionary of English v.0.48:

Lasthenia \Lasthenia\ prop. n.
   A small genus of herbs of the Pacific coast of North and
   South America.

   Syn: genus Lasthenia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Lasthenia
    n 1: small genus of herbs of Pacific coast of North and South
         America [syn: Lasthenia, genus Lasthenia]