Cycadidae

Cycadidae is a subclass of Equisetopsida in the sense used by Mark W. Chase and James L. Reveal in their 2009 article "A phylogenetic classification of the land plants to accompany APG III."^[1] This subclass comprises the cycads, which include the two families Cycadaceae and Zamiaceae.

Cycadidae
Scientific classification
Kingdom:	Plantae
Class:	Equisetopsida
Subclass:	Cycadidae Pax in K.A.E.Prantl 1894
Order:	Cycadales Pers. ex Bercht. & J.Presl 1820
Families
Cycadaceae Pers. 1807 Zamiaceae Horan. 1834

Phylogeny

The following diagram shows a likely phylogenic relationship between subclass Cycadidae and the other Equisetopsida subclasses.^[2]

Equisetopsida Marchantiidae Bryidae Anthocerotidae Lycopodiidae Equisetidae Marattiidae Ophioglossidae Polypodiidae Cycadidae Ginkgoidae Gnetidae Pinidae Magnoliidae

bryophytes lycopodiophytes monilophytes gymnosperms angiosperms

References

1. Mark W. Chase; James L. Reveal (2009). "A phylogenetic classification of the land plants to accompany APG III". Botanical Journal of the Linnean Society. 161: 122–127. doi:10.1111/j.1095-8339.2009.01002.x.
2. Maarten J. M. Christenhusz; James L. Reveal; Aljos Farjon; Martin F. Gardner; Robert R. Mill; Mark W. Chase (2011). "A new classification and linear sequence of extant gymnosperms" (PDF). Phytotaxa. 19: 55–70.