The Collaborative International Dictionary of English v.0.48:

Acropetal \A*crop"e*tal\, a. [Gr. 'a`kros summit + L. petere to
   seek.] (Bot.)
   Developing from below towards the apex, or from the
   circumference towards the center; centripetal; -- said of
   certain inflorescence.
   [1913 Webster]

WordNet (r) 3.0 (2006):

acropetal
    adj 1: of leaves or flowers; developing or opening in succession
           from base to apex [ant: basipetal]