Equisetites is an extinct genus of within Equisetaceae, a family of that reproduce by rather than seeds.[K. Sternberg, von Graf. (1833). Versuch einer geognostisch-botanischen Darstellung der Flora der Vorwelt, Heft V. Prag (1833–1838)] and contains at least 40 named species and two unnamed species,[Zauer, V. V. (1965) The Permian flora of Solikamsk. Trudy Vsesoyuznyy Nauchno-Issledovatel'skiy Geologorazvedochniy Neftyanoy Institut (VNIGRI). Paleophytological Collection.(Samoilovich,S.R.,editor) Vol. 239 p. 53- 78] 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.
[ (2005): Equisetites aequecaliginosus sp. nov., ein Riesenschachtelhalm aus der spättriassischen Formation Santa Clara, Sonora, Mexiko Equisetites. Revue de Paléobiologie'' 24(1): 331–364 German. PDf fulltext]
