Cyatheaceae

{{Short description|Family of ferns}} {{Automatic taxobox | fossil_range = {{fossil range|Late Jurassic|Recent}} | image = Cyathea glauca 02.JPG | image_caption = ''Cyathea glauca'' | taxon = Cyatheaceae | authority = Kaulf. | subdivision_ranks = Genera | subdivision = * ''Alsophila'' * ''Cyathea'' * ''Gymnosphaera'' * ''Sphaeropteris'' * †''Alsophilocaulis'' * †''Cibotiocaulis'' * †''Cyatheocaulis'' * †''Oguracaulis'' | synonyms = * Alsophilaceae Presl 1847 * Hymenophyllopsidaceae Pichi-Sermolli 1970 }}

The '''Cyatheaceae''' are a family of ferns, the scaly tree ferns, one of eight families in the order Cyatheales in the Pteridophyte Phylogeny Group classification of 2016 (PPG I).<ref name=PPGI/> Alternatively, the family may defined much more broadly (Cyatheaceae ''sensu lato'') as the only family in the Cyatheales, with the PPG I family treated as the subfamily '''Cyatheoideae'''.<ref name=ChriChas14/> The narrower circumscription is used in this article.

The family includes the world's tallest tree ferns, which reach heights up to 20 m. They are also very ancient plants, appearing in the fossil record in the late Jurassic, though the modern genera likely appeared in the Cenozoic. Cyatheaceae are the largest family of tree ferns, including about 640 species.<ref name=PPGI/> Cyatheaceae and Dicksoniaceae, together with Metaxyaceae and Cibotiaceae, do not form a strongly supported monophyletic group and could be paraphyletic, but several individual subgroups are well supported as being monophyletic. Cyatheaceae are leptosporangiate ferns, the most familiar group of monilophytes.<ref name=KoraConaMetzSchn07/>

The Cyatheaceae usually have a single, erect or creeping rhizome (stem). Their fronds (leaves) are also very large, although not as large as the tree ferns of the Marattiaceae. Some species have fronds reaching 3–4 m in length, and have a final crown width of some 6 m. The fronds are circinate before unfolding and usually pinnately or bipinnately compound, with deeply pinnately lobed leaflets. The large leaves are covered in scales and hairs, and bear sori (spore clusters) on their undersides.<ref name="Judd 2008">Judd, W.S., C.S. Campbell, E.A. Kellogg, P.F. Stevens, and M.J. Donoghue (Eds.) 2008. Plant Systematics: A Phylogenetic Approach, Third Edition. Sinauer Associates, Sunderland, Massachusetts, USA.</ref> The sori are often covered by a flap of tissue called an indusium, a useful characteristic for classifying the Cyatheaceae. Some indusia are cup-shaped (cyatheoid), while others are hood-shaped (hemitelioid), enclose the sorus (sphaeropteroid), or scaly. Like most ferns, members of the Cyatheaceae are homosporous. Cyatheaceae are found in both New and Old World tropical wet montane forests and cloud forests, with some species extending into south-temperate regions.<ref name=KoraConaMetzSchn07/> Most Cyatheaceae are terrestrial, with one being a facultative epiphyte and others having a creeping habit.

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Cyatheaceae can be distinguished from arborescent ''Dicksonia'' by the presence of scales, the position of the sori, and the morphology of sporangia and spores.<ref name="Holttum and Edwards 1983">Holttum, R.E. and P.J. Edwards. 1983. The tree-ferns of Mount Roraima and neighbouring areas of the Guayana highlands with comments on the family Cyatheaceae. Kew Bulletin 38(2): 155-188.</ref> In the Cyatheaceae, the sori occur away from the margins of the pinnules, and are elongate or rounded.

==Taxonomy== {{As of|2019}}, two different circumscriptions of the family Cyatheaceae are used, as summarized in the table below. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family is one of eight in the order Cyatheales, and has three genera.<ref name=PPGI/> In the classification of Christenhusz & Chase (2014), the family is the only one in the order Cytheales, the families of PPG I being reduced to subfamilies. It then has 13–14 genera.<ref name=ChriChas14/> The ''sensu stricto'' circumscription of PPG I is used here. {| class="wikitable" |- ! PPG I (2016) !! Christenhusz & Chase (2014) |- |Order Cyatheales A.B.Frank||Order Cyatheales A.B.Frank |- | ||  Family Cyatheaceae Kaulf. |- |  Family Thyrsopteridaceae C.Presl||   Subfamily Thyrsopteridoideae B.K.Nayar |- |  Family Loxsomataceae C.Presl||   Subfamily Loxsomatoideae Christenh. |- |  Family Culcitaceae Pic.Serm||   Subfamily Culcitoideae Christenh. |- |  Family Plagiogyriaceae Bowe||   Subfamily Plagiogyrioideae Christenh. |- |  Family Cibotiaceae Korall||   Subfamily Cibotioideae Nayer |- |  Family Metaxyaceae Pic.Serm.||   Subfamily Metaxyoideae B.K.Nayar |- |  Family Dicksoniaceae M.R.Schomb.||   Subfamily Dicksonioideae Link |- |  Family Cyatheaceae Kaulf.||   Subfamily Cyatheoideae Endl. |}

===Genera=== Since the exact number of species is not known, classification of the Cyatheaceae ''s.s.'' has had a long and controversial history, and is still undergoing revision. Three tentative clades have been developed: ''Alsophila'', ''Cyathea'', and ''Sphaeropteris''. These are frequently used as genus names. ''Cnemidaria'', ''Trichopteris'' (or ''Trichipteris''), and ''Nephelea'' (or ''Nephelia'') have also been suggested as genera. Initially, indusium and scale morphology were used to organize the Cyatheaceae into taxonomic ranks. Most recently, plastid DNA has been used, suggesting the Cyatheaceae should be split into four clades: ''Sphaeropteris'', ''Cyathea'', ''Alsophila'', and ''Gymnosphaera + A. capensis''. {{As of|2007}}, it remained unclear which of these groups should be considered genera and which subgenera.<ref name=KoraConaMetzSchn07/>

The Pteridophyte Phylogeny Group classification of 2016 (PPG I) accepts three genera, placing the ''Gymnosphaera'' clade within ''Alsophila'':<ref name=PPGI/> * ''Alsophila'' R.Br., about 275 species * ''Cyathea'' Sm., about 265 species * ''Sphaeropteris'' Bernh., about 103 species

{| class="wikitable" |- ! colspan=1 |Dong and Zuo 2018<ref name=DongZuo18/> ! colspan=1 |Nitta et al. 2022<ref>{{cite journal |last1=Nitta |first1=Joel H. |last2=Schuettpelz |first2=Eric |last3=Ramírez-Barahona |first3=Santiago |last4=Iwasaki |first4=Wataru |display-authors=et al. |year=2022 |title=An Open and Continuously Updated Fern Tree of Life |journal=Frontiers in Plant Science |volume=13 |issue= |article-number= 909768| doi=10.3389/fpls.2022.909768 |pmid= 36092417|pmc= 9449725|bibcode= 2022FrPS...1309768N|doi-access=free}}</ref> and Fern Tree of life<ref>{{cite web|last1= |first1= |last2= |display-authors=et al. |year=2022 |title=Tree viewer: interactive visualization of FTOL |url=https://fernphy.github.io/viewer.html |version=FTOL v1.3.0 |access-date=12 December 2022}}</ref> |- | style="vertical-align:top| {{Clade | style=font-size:90%;line-height:80%;width:250px |label1= |1={{clade |1=''Sphaeropteris'' |2={{clade |1=''Cyathea'' |2={{clade |1=''Alsophila'' |2=''Gymnosphaera'' }} }} }} }} | {{Clade | style=font-size:90%;line-height:80% |1={{clade |1=''Sphaeropteris'' |2={{clade |1=''Gymnosphaera'' |2={{clade |1=''Alsophila'' |2=''Cyathea'' }} }} }} }} |}

==References== {{Reflist|refs= <ref name=ChriChas14>{{Cite journal |last1=Christenhusz |first1=Maarten J.M. |last2=Chase |first2=Mark W. |date=2014 |title=Trends and concepts in fern classification |journal=Annals of Botany |volume=113 |issue=9 |pages=571–594 |doi=10.1093/aob/mct299 |pmid=24532607 |pmc=3936591 |name-list-style=amp }}</ref>

<ref name=DongZuo18>{{Cite journal |last1=Dong |first1=Shi-Yong |last2=Zuo |first2=Zheng-Yu |date=2018 |title=On the Recognition of ''Gymnosphaera'' As a Distinct Genus in Cyatheaceae |journal=Annals of the Missouri Botanical Garden |volume=103 |issue=1 |pages=1–23 |doi=10.3417/2017049 |bibcode=2018AnMBG.103....1D |s2cid=90852235 |name-list-style=amp }}</ref>

<ref name=KoraConaMetzSchn07>{{Cite journal |last1=Korall |first1=Petra |last2=Conant |first2=David S. |last3=Metzgar |first3=Jordan S. |last4=Schneider |first4=Harald |last5=Pryer |first5=Kathleen M. |date=2007 |title=A molecular phylogeny of scaly tree ferns (Cyatheaceae) |journal=American Journal of Botany |volume=94 |issue=5 |pages=873–886 |url=https://www.researchgate.net/publication/51186907 |access-date=2019-08-22 |doi=10.3732/ajb.94.5.873 |pmid=21636456 |bibcode=2007AmJB...94..873K |name-list-style=amp }}</ref>

<ref name=PPGI>{{citation |mode=cs1|author=PPG I |year=2016 |title=A community-derived classification for extant lycophytes and ferns |journal=Journal of Systematics and Evolution |volume=54 |issue=6 |pages=563–603 |doi=10.1111/jse.12229|bibcode=2016JSyEv..54..563. |s2cid=39980610 |doi-access=free }}</ref> }} * Large, M.F. and J.E. Braggins ''Tree Ferns''. Timber Press (2004). {{ISBN|0-88192-630-2}}

==External links== {{Commons category}} * [http://www.pryerlab.net/publication/fichier734.pdf Tree ferns:Monophyletic groups and their relationships as revealed by four protein-coding plastid loci] * Palacios-Rios, M. 2007. https://web.archive.org/web/20170107191324/http://www.helechos.com.mx/

Category:Cyatheaceae Category:Fern families