Marattiaceae

Marattiaceae Temporal range:
Angiopteris evectafrond
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Subclass:	Marattiidae Klinge
Order:	Marattiales Link
Family:	Marattiaceae Kaulf.
Genera
See text.
Synonyms
AngiopteridaceaeFée ex Bommer ChristenseniaceaeChing DanaeaceaeAgardh KaulfussiaceaeCampb.

Marattiaceaeis the only family of extant (living)fernsin the orderMarattiales.In thePteridophyte Phylogeny Groupclassification of 2016 (PPG I), Marattiales is the only order in the subclassMarattiidae.The family has six genera and about 110 species.Many are different in appearance from other ferns, having large fronds and fleshy rootstocks.

Description

The Marattiaceae diverged from other ferns very early in their evolutionary history and are quite different from many plants familiar to people intemperate zones.Many of them have massive, fleshy rootstocks and the largest knownfrondsof any fern. The Marattiaceae is one of two groups of ferns traditionally known aseusporangiate ferns,meaning that thesporangiumis formed from a group of cells as opposed to a leptosporangium in which there is a single initial cell.

The large fronds characteristic of the group are most readily found in the genusAngiopteris,native toAustralasia,MadagascarandOceania.These fronds may be up to 9 meters long in the speciesAngiopteris teysmannianaofJava.InJamaicathe speciesAngiopteris evectais widely naturalized and is registered as aninvasive species.The plant was introduced by CaptainBlighfromTahitias a staple food forslavesand cultivated in theCastleton Botanical Gardenin 1860. From there it was able to distribute itself throughout the eastern half of the island.

Genus Angiopteris also undergoes monoplastidic meiosis, an ancestral trait, rather than polyplastidic meiosis, and is the only known example withineuphyllophytesto do so.

Marattiain the strict sense is found in the neotropics and Hawaii. The genusEupodiumis alsoneotropical,with three species. It has fronds that are 2-5 times pinnate, distinctive stalked synangia, and awns on distal blade segments. Blade division decreases towards the apex of the frond. Plants ofEupodiumusually only have one frond per plant per year (sometimes two).

Ptisanais apaleotropicalgenus. These plants are 2-4 times pinnate, with fronds often comparable in size to those found inAngiopteris.Terminal segments usually have a prominent suture where they attach. The sporangia lack the labiate apertures ofMarattiaandEupodium,and synangia are deeply cut. The name of the genus derives from the resemblance of the synangia topearl barley.The king fern,Ptisana salicina,fromNew Zealandand theSouth Pacificand known inMāorias "para" now has been placed in this genus. Sometimes called the potato fern, this is a large fern with an edible fleshyrhizomethat is used as a food source by some indigenous peoples.

The East-Asian genusChristenseniais named in honor of the Danish pteridologistCarl Christensenis an uncommon fern with distinctive fronds resembling ahorse chestnutleaf, hence the speciesChristensenia aesculifolia,meaning horse-chestnut-leavedChristensenia.Despite the relatively diminutive size of plants in this genus, thestomataofChristenseniaare the largest known in the plant kingdom.

The genusDanaeais endemic to theNeotropics.They have bipinnate leaves with opposite pinnae, which are dimorphic, the fertile leaves much contracted, and covered below with sunken, linearsynangiadehiscing via pores.

Taxonomy

in thePteridophyte Phylogeny Groupclassification of 2016 (PPG I), Marattiaceae is the only family in the order Marattiales, which in turn is the only order in the subclass Marattiidae. Marattiidae is one of four subclasses of classPolypodiopsida(ferns), to which it is related as shown in thiscladogram,being asister grouptoPolypodiidae.

Polypodiopsida	Equisetidae Ophioglossidae Marattiidae Polypodiidae

History of classification

In the molecular phylogenetic classification of Smith et al. in 2006, the Marattiales formed the single member of the class Marattiopsida. Four genera were recognized.The class was lowered in rank to the subclass Marattiidae in the 2009 classification ofMark W. ChaseandJames L. Reveal,and subsequent systems such as Christenhusz et al. (2011).The Pteridophyte Phylogeny Group (2016) classification retains this rank. In that system, Marattiidae ismonotypicand has one order, Marattiales, one family, Marattiaceae, six genera, and an estimated 111 species.

There have long been four traditional extant genera (Angiopteris,Christensenia,DanaeaandMarattia), but phylogenetic analysis has determined the genusMarattiato be paraphyletic, and the genus has been split into three genera,Marattiain the strict sense,Eupodium,andPtisana.Christenhusz and Chase placedDanaeain subfamily Danaeoideae and the remaining genera in subfamily Marattioideae,but this subfamilial classification was not taken up by PPG I.

This fern group has a long fossil history with many extinct taxa (Psaronius,Asterotheca,Scolecopteris,Eoangiopteris,Qasimia,Marantoidea,Danaeites,Marattiopsis,Ptychocarpus,etc.).

Genera

Exploring the phylogeny of the marattialean ferns	Fern Tree of Life
Danaeoideae Danaea Marattioideae †Marattiopsis Eupodium Ptisana Christensenia Marattia Angiopteris	Danaeoideae Danaea Marattioideae Eupodium Ptisana Marattia Christensenia Angiopteris

Six genera are accepted in the PPG I classification:

• AngiopterisHoffm.
• ChristenseniaMaxon
• DanaeaSm.
• EupodiumJ.Sm.
• MarattiaSw.
• PtisanaMurdock

Several other genera have been named in the Marattiaceae, namely:Archangiopteris,Clementea,Macroglossum,Protangiopteris,ProtomarattiaandPsilodochea.These are currently treated assynonymsofAngiopteris.

Evolutionary history

Marattiaceae are considered one of the most primitive living lineages of ferns. The earliest members of the family appeared during theCarboniferous,over 300 million years ago. The group has an extensive fossil record extending from the Carboniferous into theJurassic,but post-Jurassic records are scarce.

External links

• Tree of Life Marattiaceae