The Collaborative International Dictionary of English v.0.48:

Indigofera \In`di*gof"e*ra\, n. [NL., from E. indigo + L. ferre
   to bear.] (Bot.)
   A genus of leguminous plants (family Leguminosae) having
   many species, mostly in tropical countries, several of them
   yielding indigo, esp. Indigofera tinctoria, Indigofera
   suffroticosa, and Indigofera Anil.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Indigo \In"di*go\, n.; pl. Indigoes. [F. indigo, Sp. indigo,
   indico, L. indicum indigo, fr. Indicus Indian. See Indian.]
   [1913 Webster]
   1. A kind of deep blue, one of the seven prismatic colors.
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   2. (Chem.) A blue dyestuff obtained from several plants
      belonging to very different genera and orders, such as,
      the woad, Isatis tinctoria (family Cruciferae),
      Indigofera suffroticosa, Indigofera tinctoria (family
      Leguminosae), Indigofera Anil, Nereum tinctorium,
      Polygonum tinctorium Ait. (family Polygonaceae), etc.;
      called also natural indigo. It is a dark blue earthy
      substance, tasteless and odorless, with a copper-violet
      luster when rubbed. Indigo does not exist in the plants as
      such, but is obtained by decomposition of the glycoside
      indican.
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   Note: Commercial indigo contains the essential coloring
         principle indigo blue or indigotine, with several other
         dyes; as, indigo red, indigo brown, etc., and various
         impurities. Indigo is insoluble in ordinary reagents,
         with the exception of strong sulphuric acid.
         [1913 Webster]

   Chinese indigo (Bot.), Isatis indigotica, a kind of woad.


   Wild indigo (Bot.), the American herb Baptisia tinctoria
      which yields a poor quality of indigo, as do several other
      species of the same genus.
      [1913 Webster]