Leptosporangiatae

Cinnamon fern Osmunda cinnamomea, photographed by Robbin Moran.

Belongs within: Monilophyta.
Contains: Lomariopsidaceae, Hymenophyllaceae, Gleicheniaceae, Matoniaceae, Schizaeaceae, Marsileaceae, Salviniaceae, Pteridales, Lindsaeaceae, Cyatheaceae, Dicksoniaceae.

The Leptosporangiatae include most familiar fern species. The clade is primarily characterised by distinctive sporangia (leptosporangia) of which the greater part develops from a single cell, as opposed to the multicellular-derived sporangia (eusporangia) of other ferns and fern-like plants. Known members of the Leptosporangiatae date back to the Early Permian, where they are represented by relatives of the royal ferns in the Osmundaceae (Schneider et al. 2004). Members of the Osmundaceae do not have the sporangia arranged in distinct sori (packets) as in other ferns (Allan 1961).

See also: When ferns don't look like ferns.

Synapomorphies (from Cantino et al. 2007): Leptosporangia present, originating from two cells, with sporangial stalk broad, capsule small with thin wall, annulus present, and 512 or less spores per sporangium; gametophytes with exposed antheridia and archegonia; less than 100 sperm per antheridium; first division of zygote more or less longitudinal; prone embryos with small foot; mesarch protoxylem; stem rhizomatous.

<==Leptosporangiatae [Aspidiales, Gleicheniales, Schizaeales, Polypodiales, Polypodiidae]
    |  i. s.: Lophosoria [Lophosoriaceae] J87
    |           `--L. quadripinnata J87
    |         Lomariopsidaceae J87
    |         Adiantites SS04
    |           |--A. lindsayoides SS04
    |           `--A. obtusus A38
    |--+--Grammatopteris [Guiareaceae] SS04
    |  `--Osmundaceae PS01
    |       |--Todea Willd. 1802 A61
    |       |    |--T. barbara (Linnaeus) Moore 1857 (see below for synonymy) A61
    |       |    `--T. subg. Leptopteris A61
    |       |         |--T. hymenophylloides Rich. 1832 (see below for synonymy) A61
    |       |         `--T. superba Col. 1846 [=Leptopteris superba (Col.) Presl 1848] A61
    |       `--Osmunda PS01
    |            |--O. banksiifolia SS04
    |            |--O. cinnamomea Linnaeus 1753 CD07
    |            |--O. claytoniana Linnaeus 1753 (see below for synonymy) I88
    |            |--O. japonica Thunberg 1780 [incl. O. regalis var. spectabilis (von Willdenow) Gray 1972] I88
    |            `--O. regalis YM03
    |                 |--O. r. var. regalis L54
    |                 `--O. r. var. spectabilis L54
    `--+--Hymenophyllaceae SS04
       `--+--+--Gleicheniaceae PS01
          |  |--Szea SS04
          |  `--Oligocarpia SS04
          |       |--O. leptophylla RDS03
          |       `--O. splendens [incl. O. brongniarti] A38
          `--+--+--Matoniaceae PS01
             |  `--+--Cheiropleuria YM03 [Cheiropleuriaceae KTT04]
             |     |    `--C. bicuspis YM03
             |     `--Dipteris [Dipteridaceae] PS01
             |          `--D. conjugata PS01
             `--+--+--Schizaeaceae SS04
                |  `--Lygodium Swartz 1801 A61 [Lygodiaceae B06]
                |       |--L. articulatum Rich. 1832 [incl. L. gracilescens Col. 1896] A61
                |       |--L. flexuosum Swartz 1801 [=Ophioglossum flexuosum Linnaeus 1753] B06
                |       |--L. japonicum (Thunberg) Swartz 1801 [=Ophioglossum japonicum Thunberg 1784] B06
                |       `--L. lanceolatum SS04
                `--+--+--Marsileaceae WP05
                   |  `--Salviniaceae WP05
                   `--+--+--Lonchitis hirsuta SS04
                      |  `--+--Pteridales SS04
                      |     `--+--Lindsaeaceae SS04
                      |        `--+--Dennastra SS04
                      |           `--Saccoloma SS04
                      |                |--S. elegans SS04
                      |                `--S. inaequale SS04
                      `--+--+--Cyatheaceae WP05
                         |  `--Dicksoniaceae PS01
                         `--+--Loxomataceae SS04
                            |    |--Loxsomopsis A61
                            |    `--Loxoma Br. ex Cunn. 1837 [=Loxsoma] A61
                            |         `--L. cunninghamii Br. ex Cunn. 1837 A61
                            `--Plagiogyria [Plagiogyriaceae] WP05
                                 |--P. communis Ching 1958 I88
                                 |--P. euphlebia (Kunze) Mett. 1858 [=Lomaria euphlebia Kunze 1848] I88
                                 |--P. japonica WP05
                                 |--P. pycnophylla [=Lomaria pycnophylla Kunze 1848] I88
                                 `--P. semicordata J87

Osmunda claytoniana Linnaeus 1753 [incl. Osmunda claytoniana var. vestita (Wallich) Milde 1868, Osmundastrum claytonianum var. vestitum (Wallich) Tagawa 1941] I88

Todea barbara (Linnaeus) Moore 1857 [=Acrostichum barbarum Linnaeus 1753, Osmunda barbara Thunb. 1800; incl. Todea africana Willd. 1802] A61

Todea hymenophylloides Rich. 1832 [=Leptopteris hymenophylloides (Rich.) Presl 1845; incl. T. marginata Col. 1897, T. pellucida Hook. & Grev. 1832] A61

*Type species of generic name indicated

REFERENCES

[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).

[B06] Biswas, A. 2006. Pteridophytes of Indian Botanic Garden, Howrah. Bulletin of the Botanical Survey of India 48 (1-4): 175-188.

[CD07] Cantino, P. D., J. A. Doyle, S. W. Graham, W. S. Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis & M. J. Donoghue. 2007. Towards a phylogenetic nomenclature of Tracheophyta. Taxon 56 (3): E1-E44.

[I88] Iwatsuki, K. 1988. An enumeration of the pteridophytes of Nepal. In The Himalayan Plants vol. 1 (H. Ohba & S. B. Malla, eds) The University Museum, University of Tokyo, Bulletin 31: 231-339.

[J87] Judd, W. S. 1987. Floristic study of Morne La Visite and Pic Macaya National Parks, Haiti. Bulletin of the Florida State Museum—Biological Sciences 32 (1): 1-136.

[KTT04] Klavins, S. D., T. N. Taylor & E. L. Taylor. 2004. Matoniaceous ferns (Gleicheniales) from the Middle Triassic of Antactica. Journal of Paleontology 78 (1): 211-217.

[L54] Lötschert, W. 1954. Beitrag zur Pteridophyten-Flora von Mittel-Amerika. Senckenbergiana Biologica 35 (1-2): 109-119.

[PS01] Pryer, K. M., A. R. Smith, J. S. Hunt & J. Y. Dubuisson. 2001. rbcL data reveal two monophyletic groups of filmy ferns (Filicopsida: Hymenophyllaceae). American Journal of Botany 88 (6): 1118-1130.

[RDS03] Rössler, R., J. A. Dunlop & J. W. Schneider. 2003. A redescription of some poorly known Rotliegend arachnids from the Lower Permian (Asselian) of the Ilfeld and Thuringian Forest Basins, Germany. Paläontologische Zeitschrift 77 (2): 417-427.

[SS04] Schneider, H., E. Schuettpelz, K. M. Pryer, R. Cranfill, S. Magallón & R. Lupia. 2004. Ferns diversified in the shadow of angiosperms. Nature 428: 553-557.

[WP05] Wikström, N., & K. M. Pryer. 2005. Incongruence between primary sequence data and the distribution of a mitochondrial atp1 group II intron among ferns and horsetails. Molecular Phylogenetics and Evolution 36: 484-493.

[YM03] Yatabe, Y., & N. Murakami. 2003. Recognition of cryptic species in the Asplenium nidus complex using molecular data—a progress report. Telopea 10 (1): 487-496.