The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

WordNet (r) 3.0 (2006):

amphitropous
    adj 1: (of a plant ovule) partly inverted; turned back 90
           degrees on its stalk [ant: anatropous, inverted]