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Aquatic Fern
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 dimorphic, taking on a different shape, and leaves bear anastomosing veins. Aerenchyma is frequently present in roots, shoots, and petioles (leaf stalks). The ferns of this order vary radically in form and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsilea Villosa
''Marsilea villosa'', the ihiihi ( Hawaiian) or villous waterclover ( English), is a species of fern that is endemic to the islands of Oahu, Molokai and Niihau in Hawaii. It is found exclusively in areas that experience periodic flooding and become ephemeral pools within low elevation dry forests and shrublands. Standing water allows the sporocarp to open and release spores. It also enables the resulting sperm to swim toward and fertilize female ova. For new plants to become established, the waters must subside. Sporocarps only form once the soil has dried to a certain level. Like other species in its genus, the leaves of ''M. villosa'' resemble those of a four-leaf clover. Conservation Fewer than 2,000 individual plants exist in four remaining populations. The plant was federally listed as an endangered species in 1992. References External links villosa ''Villosa'' is a genus of freshwater mussels, aquatic bivalve molluscs in the family Unionidae. Species Species ... [...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] |
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] |
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] |
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] |
Marsilea
''Marsilea'' is a genus of approximately 65 species of aquatic ferns of the family Marsileaceae. The name honours Italian naturalist Luigi Ferdinando Marsili (1656–1730). These small plants are of unusual appearance and do not resemble common ferns. Common names include water clover and four-leaf clover because of the long-stalked leaves have four clover-like lobes and are either present above water or submerged. It is worth clarifying that these plants are not clovers. The sporocarps of some Australian species are very drought-resistant, surviving up to 100 years in dry conditions. On wetting, the gelatinous interior of the sporocarp swells, splitting it and releasing a worm-like mass that carries sori, eventually leading to germination of spores and fertilization. Uses As food Sporocarps of some Australian species such as '' Marsilea drummondii'' are edible and have been eaten by Aborigines and early white settlers, who knew it under the name ngardu or nardoo. Parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenic
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic patterns amo ... [...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] |
Phytotaxa
''Phytotaxa'' is a peer-reviewed scientific journal for rapid publication on any aspect of systematic botany. It publishes on a wide range of subjects, but focuses on new species, monographs, floras, revisions, reviews, and typification issues. ''Phytotaxa'' covers all plant groups covered by the International Code of Nomenclature for algae, fungi, and plants, including diatoms, fungi, algae, lichens, mosses, hornworts, liverworts, and vascular plants), both living and fossil. The journal was established in 2009 by Maarten Christenhusz and the first issue appeared in October 2009. Authors have the option to publish open access. Abstracting and indexing The journal is abstracted and indexed in Science Citation Index Expanded, Current Contents/Agriculture, Biology & Environmental Sciences, and BIOSIS Previews. See also * Zootaxa ''Zootaxa'' is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press (Auckland, New Zealand). The jou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptosporangiate Ferns
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] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of '' Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before prin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
