Equisetites

Equisetites is an extinct genus of vascular plants within Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. The genus was named by Sternberg (1833) and contains at least 40 named species and two unnamed species, with the earliest known species being E. hemingwayi from the Westphalian of Yorkshire, England, though the affinity of this genus to modern Equistaceae is uncertain.

Systematics
Equisetites is a "wastebin taxon" uniting all sorts of large horsetails from the Mesozoic; it is almost certainly paraphyletic and would probably warrant being subsumed in Equisetum. But while some of the species placed there are likely to be ancestral to the modern horsetails, there have been reports of secondary growth in other Equisetites, and these probably represent a distinct and now-extinct horsetail lineage. Equicalastrobus is the name given to fossil horsetail strobili, which probably mostly or completely belong to the (sterile) plants placed in Equisetites.