Subordinate Taxa
Scientific Name:
Equisetaceae Michx. ex DC., Essai Propr. Méd. Pl. 49 (1804)
Type Taxon:

Terrestrial ferns.  Underground stems long-creeping, freely branching, bearing wiry roots.  Aerial stems green, erect, branching in whorls or unbranched, usually with a central hollow surrounded by two rings of smaller alternating cavities, jointed, longitudinally grooved, siliceous, glabrous, bearing leaves in sheathing whorls at the nodes.  Leaves united laterally into a sheath, toothed at the apices, equalling the number of stem grooves.  Veins undivided in each leaf.  Strobili terminal on main aerial stems, or sometimes on lateral stems, or on specialised shoots lacking chlorophyll, bearing stalked peltate sporangiophores arranged in whorls.  Several sporangia pendent from adaxial surface of heads of sporangiophores; each sporangium sessile, lacking an annulus and dehiscing by a longitudinal slit, containing 1000s of spores and elaters.  Homosporous; spores alete, spherical, attached to four coiled elaters, granulate to smooth, chlorophyllous.


A family of one genus and 15 species (Hauke 1990). The Equisetaceae is a very distinctive family of terrestrial ferns with erect aerial stems that are usually hollow, jointed and longitudinally grooved, produce whorls of branches and leaves, bear conspicuous terminal strobili comprising whorls of peltate sporangiophores, and have a base chromosome number of 108.

Traditionally the Equisetaceae has been included within the fern allies, and is clearly related to early groups of fossil plants in the Sphenophyllales and Calamitales. However, molecular evidence now indicates that the family is part of the ferns, albeit distantly related and its exact placement remains uncertain.  Pryer et al. (2004) and Smith et al. (2006) treated Equisetaceae as sister to Marattiaceae, but Rai & Graham (2010) suggested that the group is sister to the rest of the ferns.  Christenhusz et al. (2011) considered the latter position to be more consistent with the fossil record but continued to include Equisetaceae within the ferns.


Virtually cosmopolitan except for Australia and New Zealand.  Three naturalised species occur in New Zealand.

Number of species in New Zealand within Equisetaceae Michx. ex DC.
Exotic: Fully Naturalised2
Exotic: Casual1
Brownsey, P.J.; Perrie, L.R. 2015: Equisetaceae. In: Breitwieser, I; Heenan, P.B.; Wilton, A.D. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 6. Manaaki Whenua Press, Lincoln.
Candolle, A.P. de 1804: Essai sur les propriétés médicales des plantes. Didot, Paris.
Christenhusz, M.J.M.; Zhang, X.-C.; Schneider, H. 2011: A linear sequence of extant families and genera of lycophytes and ferns. Phytotaxa 19: 7–54.
Connor, H.E. 1977: The Poisonous Plants in New Zealand. Edition 2. Government Printer, Wellington.
Hauke, R.L. 1990: Equisetaceae. In: Kramer, K.U.; Green, P.S. Pteridophytes and gymnosperms. Vol. 1. In: Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. Springer-Verlag, Berlin.
Kramer, K.U.; Green, P.S. 1990: Pteridophytes and gymnosperms. Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. Vol. 1. Springer-Verlag, Berlin.
Large, M.F.; Braggins, J.E. 1991: Spore atlas of New Zealand ferns and fern allies. SIR Publishing, Wellington.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.
Pryer, K.M.; Schuettpelz, E.; Wolf, P.G.; Schneider, H.; Smith, A.R.; Cranfill, R. 2004: Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences. American Journal of Botany 91: 1582–1598.
Rai, H.S.; Graham, S.W. 2010: Utility of a large, multigene plastid data set in inferring higher-order relationships in the ferns and relatives (monilophytes). American Journal of Botany 97: 1444–1456.
Smith, A.R.; Pryer, K.M.; Schuettpelz, E.; Korall, P.; Schneider, H.; Wolf, P.G. 2006: A classification for extant ferns. Taxon 55(3): 705–731.