Eusporangiate fern

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Eusporangiate ferns
Botrychium-4.jpg
Botrychium lunaria
Scientific classification
Kingdom:
Division:
(unranked):
Eusporangiate ferns
Classes

Eusporangiate ferns are vascular spore plants, whose sporangia arise from several epidermal cells and not from a single cell as in leptosporangiate ferns. Typically these ferns have reduced root systems and sporangia that produce large amounts of spores (up to 7000 spores per sporangium in Christensenia)

There are four extant eusporangiate fern families, distributed among three classes. Each family is assigned to its own order.[1][2]

The following diagram shows a likely phylogenic placement of eusporangiate fern classes within the vascular plants.[3][4]

lycophytes (club mosses, spike mosses, quillworts)

euphyllophytes

spermatophytes (seed plants)

ferns
Psilotopsida

Psilotales (whisk ferns)

Ophioglossales (grapeferns etc.)

Equisetopsida

Equisetales (horsetails)

Marattiopsida

Marattiales

Polypodiopsida

Osmundales

Hymenophyllales

Gleicheniales

Schizaeales

Salviniales

Cyatheales

Polypodiales

eusporangiate
ferns

Cladistics[edit]

While it is generally accepted that the leptosporangiate ferns are monophyletic, it is considered to be likely that the eusporangiate ferns, as a group, are paraphyletic.[5] In each of the three examples from recently published studies, shown in the following table, it can be seen that, together, the four eusporangiate fern families do not form a single clade.

Pryer & Schuettpelz, 2009[6]
ferns

Ophioglossaceae

Psilotaceae

Equisetaceae

Marattiaceae

Leptosporangiate
ferns

Rai & Graham, 2010[7]
ferns

Equisetaceae

Ophioglossaceae

Psilotaceae

Marattiaceae

Leptosporangiate
ferns

Lehtonen, 2011[4]
ferns

Ophioglossaceae

Psilotaceae

Marattiaceae

Equisetaceae

Leptosporangiate
ferns

References[edit]

  1. ^ Alan R. Smith; Kathleen M. Pryer; Eric Schuettpelz; Petra Korall; Harald Schneider; Paul G. Wolf (2006). "A classification for extant ferns" (PDF). Taxon. 55 (3): 705–731. doi:10.2307/25065646. Archived from the original (PDF) on February 26, 2008.
  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. ^ Paul G. Wolf; Joshua P. Der; Jacob B. Davidson; Kathleen M. Pryer; Aaron M. Duffy; Amanda L. Grusz (2010). "The evolution of chloroplast genes and genomes in ferns" (PDF). Plant Molecular Biology. 76: 251–261. doi:10.1007/s11103-010-9706-4.[permanent dead link]
  4. ^ a b Samuli Lehtonen (2011). "Towards Resolving the Complete Fern Tree of Life" (PDF). PLoS ONE. 6 (10): e24851. doi:10.1371/journal.pone.0024851. PMC 3192703. PMID 22022365.
  5. ^ Kathleen M. Pryer; Eric Schuettpelz; Paul G. Wolf; Harald Schneider; Alan R. Smith; Raymond Cranfill (2004). "Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences" (PDF). American Journal of Botany. 91 (10): 1582–1598. doi:10.3732/ajb.91.10.1582. PMID 21652310.
  6. ^ Kathleen M. Pryer; Eric Schuettpelz (2009). "Ferns" (PDF). In S. Blair Hedges; Sudhir Kumar (eds.). The Timetree of Life. Oxford Biology.
  7. ^ Hardeep S. Rai; Sean W. Graham (2010). "Utility of a large, multigene plastid data set in inferring higher-order relationships in ferns and relatives (Monilophytes)" (PDF). American Journal of Botany. 97 (9): 1444–1456. doi:10.3732/ajb.0900305. PMID 21616899.