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Salviniales
The order Salviniales (formerly known as the Hydropteridales and including the former Marsileales) is an order of ferns in the class Polypodiopsida. Description Salviniales are all aquatic and differ from all other ferns in being heterosporous, meaning that they produce two different types of spore (megaspores and microspores) that develop into two different types of gametophyte (female and male gametophytes, respectively), and in that their gametophytes are endosporic, meaning that they never grow outside the spore wall and cannot become larger than the spores that produced them. The megasporangia each produce a single megaspore. In being heterosporus with endosporic gametophytes they are more similar to seed plants than to other ferns. The fertile and sterile leaves are wikt:dimorphic, dimorphic, taking on a different shape, and leaves bear anastomosis, anastomosing veins. Aerenchyma is frequently present in roots, shoots, and petiole (botany), petioles (leaf stalks). The fern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypodiidae (plant)
The Polypodiidae, commonly called leptosporangiate ferns, formerly Leptosporangiatae, are one of four subclasses of ferns, the largest of these being the largest group of living ferns, including some 11,000 species worldwide. The group has also been treated as the class Pteridopsida or Polypodiopsida, although other classifications assign them a different rank. Older names for the group include Filicidae and Filicales, although at least the "water ferns" (now the Salviniales) were then treated separately. The leptosporangiate ferns are one of the four major groups of ferns, with the other three being the eusporangiate ferns comprising the marattioid ferns (Marattiidae, Marattiaceae), the horsetails (Equisetiidae, Equisetaceae), and whisk ferns and moonworts. There are approximately 8465 species of living leptosporangiate ferns, compared with about 2070 for all other ferns, totalling 10535 species of ferns. Almost a third of leptosporangiate fern species are epiphytes. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salviniaceae
Salviniaceae (), is a family of heterosporous ferns in the order Salviniales. The Salviniaceae contain the two genera '' Azolla'' and ''Salvinia ''Salvinia'' or watermosses is a genus of free-floating aquatic ferns in the family Salviniaceae. The genus is named in honor of 17th-century Italian naturalist Anton Maria Salvini, and the generic name was first published in 1754 by French bo ...'', with about 20 known species in total. The oldest records of the family date to the Late Cretaceous. ''Azolla'' was previously placed in its own family, Azollaceae, but research has shown ''Azolla'' and ''Salvinia'' to be sister genera with the likely phylogenic relationship shown in the following diagram. References Salviniales Fern families {{Polypodiidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissues that conduct water and nutrients, and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaf, leaves called megaphylls that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled Fiddlehead fern, fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate (Polypodiidae (plant), Polypodiidae) and eusporangiate ferns, the latter group including horsetails, Psilotaceae, whisk ferns, marattioid ferns, and ophioglossoid ferns. The fern crown group, consisting of the leptosporangiates and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salvinia
''Salvinia'' or watermosses is a genus of free-floating aquatic ferns in the family Salviniaceae. The genus is named in honor of 17th-century Italian naturalist Anton Maria Salvini, and the generic name was first published in 1754 by French botanist Jean-François Séguier in ''Plantae Veronenses'', a description of the plants found around Verona. Twelve species are recognized, at least three of which (''S. molesta'', ''S. herzogii'', and ''S. minima'') are believed to be hybrids in part because their sporangia are found to be empty. ''Salvinia'' is related to the other water ferns, including the mosquito fern '' Azolla''. Recent sources include both ''Azolla'' and ''Salvinia'' in Salviniaceae, although each genus was formerly given its own family. ''Salvinia'', like the other ferns in order Salviniales, are heterosporous, producing spores of differing sizes. However, leaf development in ''Salvinia'' is unique. The upper side of the floating leaf, which appears to face the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilularia
''Pilularia'' or pillworts is a genus of unusual ferns of family Marsileaceae distributed in North Temperate regions, Ethiopian mountains, and the southern hemisphere in Australia, New Zealand, and western South America. Depending on the taxonomic revisor, the genus contains between 3 and 6 species of small plants with thread-like leaves, and creeping rhizomes. The sporangia are borne in spherical sporocarps ("pills") which form in the axils of leaves. ''Pilularia minuta'' from SW Europe is one of the smallest of all ferns. Phylogeny Recent work from Pryer Lab accepted four species of ''Pilularia'', with a fifth, ''P. novae-zealandiae'', being conspecific with ''P. novae-hollandiae''. In addition, another species, ''P. dracomontana'', has been described from South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsileaceae
Marsileaceae () is a small family of heterosporous aquatic and semi-aquatic ferns, though at first sight they do not physically resemble other ferns. The group is commonly known as the "pepperwort family" or as the "water-clover family" because the leaves of the genus ''Marsilea'' superficially resemble the leaves of a four-leaf clover. In all, the family contains three genera and 50 to 80 species with most of those belonging to ''Marsilea''. Natural history Members of the Marsileaceae are aquatic or semi-aquatic. Plants often grow in dense clumps in mud along the shores of ponds or streams, or they may grow submerged in shallow water with some of the leaves extending to float on the water surface. They grow in seasonally wet habitats, but survive the winter or dry season by losing their leaves and producing hard, desiccation-resistant reproductive structures. There are only three living genera in the family Marsileaceae. The majority of species (about 45 to 70) belon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regnellidium
Regnellidium is a monotypic genus of ferns of family Marsileaceae. The single living species, ''Regnellidium diphyllum'', the two-leaf water fern, is native to southeastern Brazil and adjacent regions of Argentina. It resembles its relatives from the genus '' Marsilea'', but has 2-lobed leaves (rather than 4). This fern is sometimes grown in aquaria. A fossil assigned to the species '' Regnellidium upatoiensis'' has been found in Cretaceous deposits of the eastern United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 .... The genus name of ''Regnellidium'' is in honour of Anders Fredrik Regnell (1807–1884), a Swedish physician and botanist. It was first described and published in Ark. Bot. Vol.3 (Issue 6) on page 2 in 1904. References Other sources * Mabberley, D. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azolla Event
The Azolla event is a paleoclimatology scenario hypothesized to have occurred in the middle Eocene epoch, around , when blooms of the carbon-fixing freshwater fern '' Azolla'' are thought to have happened in the Arctic Ocean. As the fern died and sank to the stagnant sea floor, they were incorporated into the sediment over a period of about 800,000 years; the resulting draw-down of carbon dioxide has been speculated to have helped reverse the planet from the " greenhouse Earth" state of the Paleocene-Eocene Thermal Maximum, when the planet was hot enough for turtles and palm trees to prosper at the poles, to the current icehouse Earth known as the Late Cenozoic Ice Age. Geological evidence of the event In sedimentary layers throughout the Arctic basin, a unit reaching at least 8 m in thickness (the bottom of the longest core was not recovered, but it may have reached 20 m+) is discernible. This unit consists of alternating layers; siliceous clastic layers repres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azolla
''Azolla'' (common called mosquito fern, water fern, and fairy moss) is a genus of seven species of aquatic ferns in the family Salviniaceae. They are extremely reduced in form and specialized, having a significantly different appearance to other ferns and more resembling some mosses or even duckweeds. '' Azolla filiculoides'' is one of two fern species for which a reference genome has been published. It is believed that this genus grew so prolifically during the Eocene (and thus absorbed such a large amount of carbon) that it triggered a global cooling event that has lasted to the present. ''Azolla'' may establish as an invasive plant in areas where it is not native. In such a situation, it can alter aquatic ecosystems and biodiversity substantially. Phylogeny Phylogeny of ''Azolla'' Other species include: At least six extinct species are known from the fossil record: *'' Azolla intertrappea'' Sahni & H.S. Rao, 1934 (Eocene, India) *'' Azolla berryi'' Brown, 1934 (Eocen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
