Leptosporangiate fern
Real male fern ( Dryopteris filix- mas )
The Real ferns ( Polypodiopsida, = Filicopsida ) are a class within the ferns. It includes the leptosporangiaten ferns, while ferns formerly known as eusporangiat are now placed in the classes Marratiopsida and Psilotopsida.
The class includes about 11,000 species.
Features
The characteristics of the ferns also apply to the rights ferns.
The sporangia of the Real ferns develop from a single cell. The wall of the sporangium tires consists of only one layer of cells ( leptosporangiat ). Most sporangia open with a special annulus, which helps to disperse the spores. Most 64 spores are formed per sporangium.
The majority of ferns is herbaceous and has a rhizome. This can be 70 years old in Pteridium and reach 40 meters in length. There are in the tropics and tree-like ferns with arm-thick trunks. The tribes have in youth a central protostele which merge at the age in the form of rich Siphono and Polystelen. In the vascular bundles inside the xylem and the phloem is on the outside. They are surrounded by an endodermis. There is no secondary growth. The stability of the strains coming through the leaf-trace strands, by Sklerenchymplatten and in some tree ferns about through a thick coat sprossbürtiger roots.
The leaves are megaphylls, often pinnate fronds and the classic form. The leaves grow at a double-edged apical cell and are often curled characteristic during growth.
The sporangia are sitting in large numbers at the bottom of photosynthesizing leaves ( Sporotrophophylle ). Mostly, the spore-bearing leaves no different than the sterile. An exception is about the ostrich fern. The sporangia are mostly united in Sori. The spores are usually the same size ( Isospory ), the Kleefarngewächse and Schwimmfarngewächse are heterosporous.
The prothallia ( the gametophyte ) are short-lived. With the exception of heterosporic ferns they are hermaphroditic. Only in the Australian genus Platyzoma ( Gleicheniaceae ) the prothallia are dioecious. The antheridia and archegonia occur on the underside of prothallia.
Dissemination
They are found worldwide, but their focus is in the tropics, where they are forms of only a few millimeters in size ( Didymoglossum ) developed up to 20 meters tall tuft trees.
Systematics and evolution
The oldest known fossils of ferns leptosporangiaten date from the early Carboniferous. At the end of the Carboniferous, there were at least six families. In Perm, Triassic and Jurassic of these were representatives still existing families replaced ( Osmundaceae, Schizaeaceae, Matoniaceae, Dipteridaceae and others). Today's largest with 80 percent of all species of the order Polypodiales has its diversity is achieved only from the Cretaceous, ie parallel to the angiosperms.
The Real ferns are in the scheme of Smith et al used here. (2006 ) can be subdivided as follows:
- Order Osmundales Family Osmundaceae
- Family skin ferns ( Hymenophyllaceae ) (incl. Trichomanaceae )
- Family Gleicheniaceae (including Dicranopteridaceae, Stromatopteridaceae )
- Family Dipteridaceae (including Cheiropleuriaceae )
- Family Matoniaceae
- Family Lygodiaceae
- Family Anemiaceae (including Mohriaceae )
- Family Schizaeaceae
- Family Kleefarngewächse ( Marsileaceae ) (incl. Pilulariaceae )
- Family Schwimmfarngewächse ( Salviniaceae ) (incl. Azollaceae )
- Family Thyrsopteridaceae
- Family Loxomataceae
- Family Culcitaceae
- Family Plagiogyriaceae
- Family Cibotiaceae
- Family Cyatheaceae (including Alsophilaceae, Hymenophyllopsidaceae )
- Family Dicksoniaceae (including Lophosoriaceae )
- Family Metaxyaceae
- Family Lindsaeaceae (including Cystodiaceae, Lonchitidaceae )
- Family Saccolomataceae
- Family Dennstaedtiaceae (including Hypolepidaceae, Monachosoraceae, Pteridiaceae )
- Family Pteridaceae (including Acrostichaceae, Actiniopteridaceae, Adiantaceae, Anopteraceae, Antrophyaceae, Ceratopteridaceae, Cheilanthaceae, Cryptogrammaceae, Hemionitidaceae, Negripteridaceae, Parkeriaceae, Platyzomataceae, Sinopteridaceae, Taenitidaceae, Vittariaceae )
- Family Aspleniaceae
- Family Thelypteridaceae
- Family Woodsiaceae (including Athyriaceae, Cystopteridaceae )
- Family Blechnaceae (including Stenochlaenaceae )
- Family Onocleaceae
- Family Dryopteridaceae (including Aspidiaceae, Bolbitidaceae, Elaphoglossaceae, Hypodematiaceae, Peranemataceae )
- Family Lomariopsidaceae (including Nephrolepidaceae )
- Family Tectariaceae
- Family Oleandraceae
- Family Davalliaceae
- Tüpfelfarngewächse family ( Polypodiaceae ) (incl. Drynariaceae, Grammitidaceae, Gymnogrammitidaceae, Loxogrammaceae, Platyceriaceae, Pleurisoriopsidaceae )
For the individual genera of the family, see classification of ferns.
Among the leptosporangiaten ferns there are the following extinct families:
- Guaireaceae
- Botryopteridaceae
- Anachoropteridaceae
- Kaplanopteridaceae
- Psalixochlaenaceae
- Sermayaceae
- Tedeleaceae
- Skaaripteridaceae
- Tempskyaceae