Equisetopsida sensu lato

Equisetopsida sensu lato Temporal range: Late Silurian–Recent PreЄ Є O S D C P T J K Pg N
Land plants
Scientific classification
Kingdom:	Plantae
Division:	Streptophyta
Class:	Equisetopsida C. Agardh 1825
Subclasses
About 13 subclasses. See text.
Synonyms
Embryophyta

Equisetopsida is the name of a class of plants that traditionally contains the single genus Equisetum (horsestails). However in 2009, in an article titled "A phylogenetic classification of the land plants to accompany APG III," Mark W. Chase and James L. Reveal proposed a much broader sense for the Equisetopsida class name. In their system, Equisetopsida includes all land plants (embryophytes). Their rationale was that "If the major clades of green algae are recognized as classes, then all land plants, the embryophytes, should be included in a single class..."^[1]

Subclasses

The class Equisetopsida sensu Chase & Reveal, 2009, contains the following subclasses. Traditional divisions and classes, along with common names are shown in parentheses.^[1]

• bryophytes (non-vascular plants)
  • Subclass Marchantiidae Engl. 1893 (div. Marchantiophyta, 3 classes - liverworts)
  • Subclass Bryidae Engl. 1892 (div. Bryophyta, class Bryopsida - moss)
  • Subclass Anthocerotidae Engl. 1893 (div. Anthocerotophyta, 2 classes - hornwort)

• lycopodiophytes
  • Subclass Lycopodiidae Bek. 1863 (div. Lycopodiophyta, 2 classes - clubmoss, spikemoss, quillworts)

• monilophytes (ferns)^[2]
  • Subclass Equisetidae Warm. 1883 (class Equisetopsida, s.s. - horsetails)
  • Subclass Ophioglossidae Klinge 1882 (class Psilotopsida - whisk ferns, grape-ferns, moonworts)
  • Subclass Marattiidae Klinge 1882 (class Marattiopsida - marattioid ferns)
  • Subclass Polypodiidae Cronquist, Takht. & W. Zimm. 1966 (class Polypodiopsida - polypod ferns)
  • Subclass Psilotidae Reveal 1996 [merged into Ophioglossidae by Christenhusz, 2011]

• gymnosperms^[3]
  • Subclass Cycadidae Pax 1894 (div. Cycadophyta, class Cycadopsida - cycads)
  • Subclass Ginkgoidae Engl. 1897 (div. Ginkgophyta, class Ginkgoopsida, one extant genus: Ginko)
  • Subclass Gnetidae Pax 1894 (div. Gnetophyta, class Gnetopsida - gnetophytes)
  • Subclass Pinidae Cronquist, Takht. & W. Zimm. 1966 (div. Pinophyta, class Pinopsida - conifers)

• angiosperms^[4]
  • Subclass Magnoliidae Novák ex Takht. 1967 (Angiosperms - flowering plants)

Phylogeny

The following diagram shows a likely phylogenic relationship between the Equisetopsida subclasses.

Equisetopsida  Marchantiidae   Bryidae   Anthocerotidae   Lycopodiidae   Equisetidae   Ophioglossidae   Marattiidae   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, Xian-Chun Zhang & Harald Schneider (2011). "A linear sequence of extant families and genera of lycophytes and ferns" (PDF). Phytotaxa 19: 7–54.
3. 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.
4. James L. Reveal & Mark W. Chase (2011). "APG III: Bibliographical Information and Synonymy of Magnoliidae" (PDF). Phytotaxa 19: 71–134.