The Collaborative International Dictionary of English v.0.48:

Ginkgophyta \Ginkgophyta\, Ginkgophytina \Ginkgophytina\,
Ginkgopsida \Ginkgopsida\n. (Bot.)
   A division of trees comprising the ginkgos. In some systems
   it is classified as a class (Ginkgopsida) and in others as a
   subdivision (Ginkgophytina or Ginkgophyta); used in some
   classifications for one of five subdivisions of
   Gymnospermophyta.

   Syn: Ginkgopsida, class Ginkgopsida, subdivision
        Ginkgophytina.
        [WordNet 1.5] ginmill

WordNet (r) 3.0 (2006):

Ginkgopsida
    n 1: ginkgos: in some systems classified as a class and in
         others as a subdivision; used in some classifications for
         one of five subdivisions of Gymnospermophyta [syn:
         Ginkgopsida, class Ginkgopsida, Ginkgophytina, class
         Ginkgophytina, subdivision Ginkgophytina, subdivision
         Ginkgophyta]