Marattiopsida
Encyclopedia
Class Marattiopsida is a group of fern
s containing a single order, Marattiales, and family, Marattiaceae. Class Marattiopsida diverged from other ferns very early in their evolutionary history and are quite different from many plants familiar to people in temperate zones
. Many of them have massive, fleshy rootstocks and the largest known frond
s of any fern. The Marattiaceae is one of two groups of ferns traditionally known as eusporangiate fern
, meaning that the sporangium
is formed from a group of cells vs the leptosporangium in which there is a single initial cell. There have long been four traditional extant genera (Angiopteris
, Christensenia
, Danaea
and Marattia
), but recent genetic/cladistic analysis has determined the genus Marattia to be paraphyletic, and the genus has been split into three genera, the two new ones being Eupodium
and Ptisana
. This fern group has a long fossil history with many extinct taxa (Psaronius
, Asterotheca, Scolecopteris, Eoangiopteris, Qasimia, Marantoidea, Danaeites, Marattiopsis, etc.)
In this group, such fronds are found in the genus Angiopteris
, native to Australasia
, Madagascar
and Oceania
. These fronds may be up to 9 meters long in the species Angiopteris teysmanniana of Java
. In Jamaica
the species Angiopteris evecta
is widely naturalized and is registered as an invasive species
. The plant was introduced by Captain Bligh
from Tahiti
as a staple food for slaves and cultivated in the Castleton Gardens in 1860. From there it was able to distribute itself throughout the eastern half of the island.
Another East-Asian genus is Christensenia
, a peculiar fern with fronds resembling a horse chestnut leaf. That is why the species is called Christensenia aesculifolia, meaning Christensen's chestnut-leaf. Carl Christensen
was a famous Danish fern botanist.
The most widespread genus in Marattiaceae is the pantropical
Marattia
, usually occurring at higher elevations. These are also large ferns with globular rhizomes, but fronds can be up to 4 times pinnate. The sporangia are fused into bivalvate structures called a synangium.
The fourth genus Danaea
is endemic to the Neotropics. They have bipinnate leaves with opposite pinnae, which are dimorphic, the fertile leaves much contracted, and covered below with sunken synangia.
The genus Eupodium
is also neotropical, with two species. It has fronds that are 2-5 times pinnate, stalked synangia, and awns on the adaxial side of distal blade segments. Blade division decreases towards the apex of the frond. Plants of Eupodium usually only have one frond per plant per year (sometimes two).
Ptisana
is a paleotropical genus. These plants are 2-4 times pinnate. Terminal segments usually have a prominent suture where they attach. The sporangia lack the labiate apertures of Marattia and Eupodium, and synangia are deeply cut. The King Fern, Ptisana salicina, from New Zealand
and the South Pacific
and known in Māori
as para now has been placed in this genus. Sometimes called the Potato Fern, this is a large fern with an edible fleshy rhizome
that is used as a food source by some indigenous peoples.
Several other genera have been named in the Marattiaceae, namely: Archangiopteris, Macroglossum, Protangiopteris, and Protomarattia. These are all synonyms of Angiopteris.
According to recent molecular studies it appears that these eusporangiate ferns may be a sister group to the horsetails (Equisetaceae
). Both groups are certainly of ancient lineage.
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s containing a single order, Marattiales, and family, Marattiaceae. Class Marattiopsida diverged from other ferns very early in their evolutionary history and are quite different from many plants familiar to people in temperate zones
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
. Many of them have massive, fleshy rootstocks and the largest known frond
Frond
The term frond refers to a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...
s of any fern. The Marattiaceae is one of two groups of ferns traditionally known as eusporangiate fern
Eusporangiate fern
Eusporangiate ferns are vascular spore plants, whose sporangia arise from several epidermal cells and not from a single cell as in leptosporangiate ferns...
, meaning that the sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
is formed from a group of cells vs the leptosporangium in which there is a single initial cell. There have long been four traditional extant genera (Angiopteris
Angiopteris
Angiopteris is a genus of huge evergreen ferns from the Marattiaceae family, found throughout the paleotropics from Madagascar to the South Pacific islands...
, Christensenia
Christensenia
Christensenia is a genus of ferns in the botanical family Marattiaceae. The genus is confined to the Indo-Malayan region. The basal chromosome number for this genus is 2n=80....
, Danaea
Danaea
Danaea Sm. is a fern genus of approximately 50 species in the eusporangiate fern family Marattiaceae.they are small to intermediately large ferns with erect or creeping rhizomes and usually once pinnate leaves with opposite pinnae. The fertile leaves are contracted, acrostichoid and covered below...
and Marattia
Marattia
Marattia is a small genus of primitive, large, fleshy ferns. It is the type genus of the family Marattiaceae. Formerly considered to be a much larger genus, recent genetic analysis by Murdock demonstrated its serious paraphyly, splitting off the genera Ptisana and Eupodium....
), but recent genetic/cladistic analysis has determined the genus Marattia to be paraphyletic, and the genus has been split into three genera, the two new ones being Eupodium
Eupodium
Eupodium is a genus of ferns in the family Marattiaceae native to the Neotropics. Traditionally, many taxonomists have included Eupodium within the genus Marattia...
and Ptisana
Ptisana
Ptisana is a genus in the eusporangiate fern family Marattiaceae, comprising species historically treated in the genus Marattia. The establishment of this genus follows the 2008 work by Andrew G. Murdock, which supported recognition of this group on the basis of genetic analysis and morphology...
. This fern group has a long fossil history with many extinct taxa (Psaronius
Psaronius
Psaronius was a Marattialean tree fern which grew to 10-15m in height, and is associated with leaves of the organ genus Pecopteris....
, Asterotheca, Scolecopteris, Eoangiopteris, Qasimia, Marantoidea, Danaeites, Marattiopsis, etc.)
In this group, such fronds are found in the genus Angiopteris
Angiopteris
Angiopteris is a genus of huge evergreen ferns from the Marattiaceae family, found throughout the paleotropics from Madagascar to the South Pacific islands...
, native to Australasia
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
, Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
and Oceania
Oceania ecozone
Oceania is one of the WWF ecozones, and unique in not including any continental land mass. The ecozone includes the Pacific Ocean islands of Micronesia, the Fijian Islands, and most of Polynesia...
. These fronds may be up to 9 meters long in the species Angiopteris teysmanniana of Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
. In Jamaica
Jamaica
Jamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
the species Angiopteris evecta
Angiopteris evecta
Angiopteris evecta, commonly known as the Giant Fern, is a rare plant occurring in eastern and northern Australia. Also found growing in nearby islands such as New Guinea and various places in Polynesia and Melanesia. Listed as endangered by extinction in New South Wales, where it has been recorded...
is widely naturalized and is registered as an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. The plant was introduced by Captain Bligh
William Bligh
Vice Admiral William Bligh FRS RN was an officer of the British Royal Navy and a colonial administrator. A notorious mutiny occurred during his command of HMAV Bounty in 1789; Bligh and his loyal men made a remarkable voyage to Timor, after being set adrift in the Bounty's launch by the mutineers...
from Tahiti
Tahiti
Tahiti is the largest island in the Windward group of French Polynesia, located in the archipelago of the Society Islands in the southern Pacific Ocean. It is the economic, cultural and political centre of French Polynesia. The island was formed from volcanic activity and is high and mountainous...
as a staple food for slaves and cultivated in the Castleton Gardens in 1860. From there it was able to distribute itself throughout the eastern half of the island.
Another East-Asian genus is Christensenia
Christensenia
Christensenia is a genus of ferns in the botanical family Marattiaceae. The genus is confined to the Indo-Malayan region. The basal chromosome number for this genus is 2n=80....
, a peculiar fern with fronds resembling a horse chestnut leaf. That is why the species is called Christensenia aesculifolia, meaning Christensen's chestnut-leaf. Carl Christensen
Carl Christensen
Carl Frederik Albert Christensen was a Danish systematic botanist. He graduated in natural history from the University of Copenhagen under professor Eugenius Warming. He was first school teacher in Copenhagen, later superintendent at the Botanical Museum. He was a specialist in ferns and published...
was a famous Danish fern botanist.
The most widespread genus in Marattiaceae is the pantropical
Pantropical
In biogeography, a pantropical distribution one which covers tropical regions of all of the major continents, i.e. in Africa, in Asia and in the Americas. Examples include the plant genera Acacia and Bacopa....
Marattia
Marattia
Marattia is a small genus of primitive, large, fleshy ferns. It is the type genus of the family Marattiaceae. Formerly considered to be a much larger genus, recent genetic analysis by Murdock demonstrated its serious paraphyly, splitting off the genera Ptisana and Eupodium....
, usually occurring at higher elevations. These are also large ferns with globular rhizomes, but fronds can be up to 4 times pinnate. The sporangia are fused into bivalvate structures called a synangium.
The fourth genus Danaea
Danaea
Danaea Sm. is a fern genus of approximately 50 species in the eusporangiate fern family Marattiaceae.they are small to intermediately large ferns with erect or creeping rhizomes and usually once pinnate leaves with opposite pinnae. The fertile leaves are contracted, acrostichoid and covered below...
is endemic to the Neotropics. They have bipinnate leaves with opposite pinnae, which are dimorphic, the fertile leaves much contracted, and covered below with sunken synangia.
The genus Eupodium
Eupodium
Eupodium is a genus of ferns in the family Marattiaceae native to the Neotropics. Traditionally, many taxonomists have included Eupodium within the genus Marattia...
is also neotropical, with two species. It has fronds that are 2-5 times pinnate, stalked synangia, and awns on the adaxial side of distal blade segments. Blade division decreases towards the apex of the frond. Plants of Eupodium usually only have one frond per plant per year (sometimes two).
Ptisana
Ptisana
Ptisana is a genus in the eusporangiate fern family Marattiaceae, comprising species historically treated in the genus Marattia. The establishment of this genus follows the 2008 work by Andrew G. Murdock, which supported recognition of this group on the basis of genetic analysis and morphology...
is a paleotropical genus. These plants are 2-4 times pinnate. Terminal segments usually have a prominent suture where they attach. The sporangia lack the labiate apertures of Marattia and Eupodium, and synangia are deeply cut. The King Fern, Ptisana salicina, from New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
and the South Pacific
Oceania
Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...
and known in Māori
Maori language
Māori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
as para now has been placed in this genus. Sometimes called the Potato Fern, this is a large fern with an edible fleshy rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
that is used as a food source by some indigenous peoples.
Several other genera have been named in the Marattiaceae, namely: Archangiopteris, Macroglossum, Protangiopteris, and Protomarattia. These are all synonyms of Angiopteris.
According to recent molecular studies it appears that these eusporangiate ferns may be a sister group to the horsetails (Equisetaceae
Equisetaceae
Equisetaceae, sometimes called the horsetail family, is the only extant family of the class Equisetales, with one surviving genus, Equisetum, which comprises about twenty species.- Evolution and systematics :...
). Both groups are certainly of ancient lineage.