| Noun | 1. | Cycadopsida - palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta)class - (biology) a taxonomic group containing one or more orders class Gymnospermae, division Gymnospermophyta, Gymnospermae, Gymnospermophyta - plants having naked seeds not enclosed in an ovary; in some systems considered a class (Gymnospermae) and in others a division (Gymnospermophyta); comprises three subdivisions (or classes): Cycadophytina (class Cycadopsida) and Gnetophytina (class Gnetopsida) and Coniferophytina (class Coniferopsida); in some classifications the Coniferophytina are divided into three groups: Pinophytina (class Pinopsida) and Ginkgophytina (class Ginkgopsida) and Taxophytina (class Taxopsida) Cycadales, order Cycadales - primitive tropical gymnosperms abundant in the Mesozoic, now reduced to a few scattered tropical forms | |