Acrostichum aureum (Fern taxa)
This species is more commonly known as the Golden Mangrove Fern and is native to the north of Western Australia. It is a large understory fern which can grow up to 4 metres high and is often as broad as it is tall (Spooner 1997). The root system is visible above the ground and is sturdily built with large scales on its surface. Its leaves are dull green to golden green in colour and have a leathery texture. Fertile leaflets grow at the tips of the fronds with sporangia on their underside(Spooner 1997).
Its habitat is often muddy or salty soils on moist ground in and around mangroves. It has a high salt water tolerance and can be described as semi aquatic but does not withstand prolonged immersion (Hill 2006).
Acrostichum aureum has a conservation code of 1 on the Conservation Codes for Western Australian Flora and Fauna list. This list states that it is a poorly known species and has not yet been adequately surveyed and evaluated within Western Australia to determine its conservation status.
On the IUCN Red List Acrostichum aureum is listed as of least concern. It is a wide spread common species with no major threats to its survival. It is a fast growing, robust species which can take over disturbed mangroves (Ellison et al 2012).
This species is more commonly known as the Golden Mangrove Fern which occurs in mangrove swamps, on coastal cliffs and nearby tablelands often in muddy or salty soils on moist ground.
The large understory fern and can grow up to 4 metres high (Spooner 1997). The root system is partly above ground and supports the plant, originating from either the stem or leaf. It is sturdily built and can grow either along the ground or standing upright (Spooner 1997). It has large scales on the root surface which grow to 4cm long (Florabase of Western Australia).
The fronds of the fern usually arch around the edges of the plant, but tend to be more erect near the centre. Each has a stalk that is approximately one third of the total frond length and is covered with scales at the base(Spooner 1997).
There are a great number of individual leaves which are dull green to golden green in colour with complete boarders. Their texture is leathery and they are difficult to bend or flex and have no hairs. They are however simple in undeveloped ferns. Each leaflet is rectangular in shape and longer than tit is wide with a readily visible stalk (Spooner 1997).
Fertile leaflets occur at the end of the blade with sterile leaflets on the lower margins. The sterile leaflets grow to 35cm long and 4-5cm wide and have a short abrupt point, lacking an apex. The fertile leaflets are similar in shape but are smaller. The veins of the leaflets are tertiary and form a close network of branching, six sided mesh with a framework of conducting or supporting tissues showing no protruding parts (Spooner 1997).
The sporangia cover the lower surface of the fertile leaflet with sterile filaments growing among them in threadlike forms. These sporangia are made up of several cells which have four lateral planes in addition to a top and bottom (Spooner 1997).
A link to the species page within Flora Base of Western Australia http://florabase.dpaw.wa.gov.au/search/quick?q=Acrostichum+aureum
A link to the species page within The Atlas of Living Australia http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:apni.taxon:26...
Acrostichum aureum has a high salt water tolerance and can be described as semi aquatic but does not withstand prolonged immersion (Hill 2006). It also has the ability to take over in areas where mangrove forests or wetlands have been disturbed(Hill 2006). They can become pest-like in quantity (Ellison et al 2010).
The species is poorly known or there is very little literature on the subject possibly due to continuing confusion with like species, A. speciosum (Ellison et al 2010).
Acrostichum aureum occurs across the tropics worldwide. It is native to Western Australia and is often found in mangrove swamps, on coastal cliffs and nearby tablelands. Within Australia it is found in the northern territory and in Eastern Queensland (Spooner 1997).
A link to the state wide distribution of Ascrosticum aureum within Florabase of Western Australia http://florabase.dpaw.wa.gov.au/browse/profile/20889
A link to the worldwide distribution of Ascrosticum aureum http://unsw.discoverlife.org/mp/20m?kind=Acrostichum+aureum&guide=TWA
The common habitat of Acrostichum aureum within Australia is mangrove swamps, on coastal cliffs and nearby tablelands often in muddy or salty soils on moist ground (Spooner 1997).
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