Source : Webster's Revised Unabridged Dictionary (1913)

Amphitropal \Am*phit"ro*pal\ (-pal), Amphitropous
\Am*phit"ro*pous\ (-p[u^]s), a. [Gr. 'amfi` + tre`pein to turn.]
   (Bot.)
   Having the ovule inverted, but with the attachment near the
   middle of one side; half anatropous.

Source : WordNet®

amphitropous
     adj : (of a plant ovule) partly inverted; turned back 90 degrees
           on its stalk [ant: {anatropous}]