(biology) a taxonomic group containing one or more orders

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)

primitive tropical gymnosperms abundant in the Mesozoic, now reduced to a few scattered tropical forms

fossil gymnospermous plants of the Carboniferous

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)

primitive tropical gymnosperms abundant in the Mesozoic, now reduced to a few scattered tropical forms

fossil gymnospermous plants of the Carboniferous