Contemporary Circumscription Compared with A Utah Flora 4th ed.

Bio430

Equisetaceae

No differences at the family level.  Equisetaceae has long been recognized as distinct, with various fossil relatives, and all of this diversity treated at the division/phylum or class level.  Contemporary views differ only in recognizing that this unique clade is more closely related to ‘true’ ferns than previously thought, and is derived within the monophyletic monilophyte clade.

Key Features

The jointed, hollow stem morphology is distinctive and you shouldn’t need to look beyond this feature to recognize this family. Some species are monomorphic and others are dimorphic. Leaves are small and whorled at the nodes. Sporangia are clustered on sporangiophores grouped into a strobilus.  Spores are green and bear elaters.