Ginkgoopsida is a proposed
class
Class, Classes, or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used d ...
of
gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
s defined by Sergei V. Meyen in 1984 to encompass
Ginkgoales (which contains the living ''
Ginkgo
''Ginkgo'' is a genus of non-flowering seed plants, assigned to the gymnosperms. The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, , and ''Ginkgo'' is n ...
'') alongside a number of extinct seed plant groups, which he considered to be closely related based on similarities of morphology of pollen, seeds, cuticles, short shoots and leaves. The validity of this group as a whole has been considered questionable by other authors, who consider that it is unlikely to be
monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
. Other authors have used the class as a monotypic grouping, including only Ginkgoales. Some authors have used the clade Ginkgophyta to encompass both Ginkgoales and
Czekanowskiales/Leptostrobales, which are suggested to be closely related groups.
References
{{Taxonbar, from=Q10788836
Ginkgophyta
Plant classes