Marattiaceae
Angiopteris evecta
The Marattiaceae are a family of ferns and alone constitute the class Marattiopsida.
- 5.1 Literature
- 5.2 Notes and references
Features
Roots and stem
The extant species have large fleshy roots with polyarchem ( vielstrahligem ) xylem. The root hairs are multicellular. All organs are pervaded by mucus channels. The rhizome is fleshy, short, erect or creeping, and has a polycyclic Diktyostele. Other species have a short, bulbous trunk ( Angiopteris ). The young master has a protostele. Later, she shares a Polystele, wherein the strain in thickness increases. The Farnstamm therefore has a cone shape with the top down, secondary growth is missing. Some recent forms have a siphonostele. The stem base, we amplified by the dial feet that are left after the leaf fall leaf bases. Also adventitious roots contribute to stability.
Leaves and sporangia
At the trunk sits a bunch of fronds. These are a few meters long and usually feathered one or more times. Some species, such as Danaea simplicifolia, have undivided leaves. In youth, the leaves are rolled and have at the base a large, fleshy stipule pair. The leaves are fleshy. On sheet as at the pinnae sit joints ( pulvini ). The Blattnervatur is open. The xylem of the petiole is polycyclic. Stem and leaf blades are occupied by dandruff.
The sporangia sit on the underside of leaves. So there is no separation in sterile and fertile leaves, there are Sporotrophophylle. The sporangia are isospor. In some species they are fused to synangia side: these are capsule -like, pleated and jump at maturity on. In others, the sporangia are summarized free or in clusters ( sori ). The sporangium consists of more than one cell layer ( eusporangiat ) and have no annulus. Each sporangium is 1,000 to 7,000 spores.
Gametophyte
The prothallia are long-lived (up to several years) and have endophytic mycorrhizal fungi. In contrast to the Psilotopsida but they are green and autotrophic. The thallus is multilayered, liver moss -like and designed from the ground surface. The antheridia and archegonia sit at the bottom and are sunk.
The basic chromosome number is x = 40 (rarely 39).
Occurrence
The Marattiaceae grow in tropical forests. Marattia is pantropical distributed, Angiopteris and Christensenia are in East and Southeast Asia native, Danaea in South America. The greatest diversity of species they reach in the Malay region. They grow terrestrial, rarely on rocks.
Paleontology
The oldest fossils of Marattiales are known from the Carboniferous. Especially in the Rotliegend they were quite diverse. They formed trees whose trunks were wurzelumkleidet and up to 10 meters high were ( Asterotheca arborescens ). At that time, they dominated on the prevalent today leptosporangiaten ferns. Megaphyton marked by two lines arranged fronds.
System
There are four extant genera with around 150 species. The group is monophyletic.
- Angiopteris Hoffm, with - depending on the author - one or up to about 100 species, including. : Bootfarn ( Angiopteris evecta ( G. Forst. ) Hoffm. ), Which occurs from Madagascar to tropical Asia and the Western Pacific
- . Marattia alata Sw, Origin: West Indies, tropical South America
- . Marattia cicutifolia Kaulf, Origin: Southern Brazil
- Marattia fraxinea J. Sm, Origin: tropical Africa, tropical Asia, Australia, New Zealand
Some authors conduct a fifth genus Archangiopteris, this is, however, usually too Angiopteris. Danaea and Christensenia are sometimes placed in their own families.