The Collaborative International Dictionary of English v.0.48:

Abruptly pinnate \Abruptly pinnate\, abruptly-pinnate
\abruptly-pinnate\adj.
   1. (Bot.) pinnate with a pair of leaflets at the apex, i.e.
      without an odd leaflet, or other appendage, at the end; --
      said of a leaf shape

   Syn: even-pinnate, paripinnate
        [1913 Webster + WordNet 1.5]