The Collaborative International Dictionary of English v.0.48:

Tephrosia \Te*phro"si*a\, n. [NL., fr. Gr. ? ash-colored, from ?
   ashes.] (Bot.)
   A genus of leguminous shrubby plants and herbs, mostly found
   in tropical countries, a few herbaceous species being North
   American. The foliage is often ashy-pubescent, whence the
   name.
   [1913 Webster]

   Note: The Tephrosia toxicaria is used in the West Indies and
         in Polynesia for stupefying fish. T. purpurea is used
         medicinally in the East Indies. T. Virginia is the
         goat's rue of the United States.
         [1913 Webster]

WordNet (r) 3.0 (2006):

Tephrosia
    n 1: genus of tropical and subtropical herbs or shrubs: hoary
         peas [syn: Tephrosia, genus Tephrosia]