Hedeoma pulegioides

from WordNet (r) 3.0 (2006)

Hedeoma pulegioides
    n 1: erect hairy branching American herb having purple-blue
         flowers; yields an essential oil used as an insect
         repellent and sometimes in folk medicine [syn:
         {pennyroyal}, {American pennyroyal}, {Hedeoma pulegioides}]

from The Collaborative International Dictionary of English v.0.48

Pennyroyal \Pen`ny*roy"al\, n. [A corruption of OE. puliall
   royal. OE. puliall is ultimately derived fr. L. puleium, or
   pulegium regium (so called as being good against fleas), fr.
   pulex a flea; and royal is a translation of L. regium, in
   puleium regium.] (Bot.)
   An aromatic herb ({Mentha Pulegium}) of Europe; also, a North
   American plant ({Hedeoma pulegioides}) resembling it in
   flavor.
   [1913 Webster]

   {Bastard pennyroyal} (Bot.) See {Blue curls}, under {Blue}.
      [1913 Webster]