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Azolla Nilotica
''Azolla nilotica'' is a medium-sized floating fern, that naturally occurs in the Nile and in eastern and central Africa. It is assigned to the family Salviniaceae. Description ''Azolla nilotica'' is a floating water-bound fern of up to long, with a long, horizontal, branched, hairy rhizome of up to thick. Side branches are alternately set. The hairy roots spring in bundles from the nodes. Each leaf consists of an elliptic to broadly ovate green upper lobe of up to long, with a rounded or broadly pointed tip, with a nobbly middle and a broad translucent edge. The lower lobe lacks colour, is smaller, thinner and contains a cavity that holds the symbiont cyanophyte, that fixes aerial nitrogen making nitrate available to the plant. ''Azolla'' species have two types of spores (a state called heterosporous), small macrospores and minute microspores. The spore forming organs (called sporocarps) grow in the axils of the older leaves. In case of ''A. nilotica'', the sporocarps occ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decne
Joseph Decaisne (7 March 1807 – 8 January 1882) was a French botanist and agronomist. He became an ''aide-naturaliste'' to Adrien-Henri de Jussieu (1797-1853), who served as the chair of rural botany. It was during this time that he began to study plants brought back by various travelers like those of Victor Jacquemont (1801-1832) from Asia. Decaisne used applied research, most notably on the agronomy of the madder, the yam and the ramie. He was also interested in algae. Biography Although born in Brussels, Belgium, he exercised his activity exclusively in Paris. He entered in 1824 as a gardener at the ''Muséum national d'histoire naturelle'' (French museum of natural history) and became, in 1832, head of the ''carré des semis'' section. He also worked at the '' Jardin des Plantes'' and collaborated with Asa Gray. In 1847 he chaired Statistical Agriculture department in the College de France. In 1850, Decaisne followed Charles-François Brisseau de Mirbel (1776-1854) as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyperus Papyrus
''Cyperus papyrus'', better known by the common names papyrus, papyrus sedge, paper reed, Indian matting plant, or Nile grass, is a species of aquatic flowering plant belonging to the sedge family Cyperaceae. It is a tender herbaceous perennial, native to Africa, and forms tall stands of reed-like swamp vegetation in shallow water. Papyrus sedge (and its close relatives) has a very long history of use by humans, notably by the Ancient Egyptians (as it is the source of papyrus paper, one of the first types of paper ever made). Parts of the plant can be eaten, and the highly buoyant stems can be made into boats. It is now often cultivated as an ornamental plant. In nature, it grows in full sun, in flooded swamps, and on lake margins throughout Africa, Madagascar, and the Mediterranean countries. It has been introduced outside its range to tropical regions worldwide (such as the Indian subcontinent, South America, and the Caribbean). Description This tall, robust aquatic pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 spores (megaspores and microspores) that develop into two different types of gametophytes (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] |
Flora Of Africa
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used indiscriminately.Thurmann, J. (1849). ''Essai de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plants Described In 1867
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AlgaeBase
AlgaeBase is a global species database of information on all groups of algae, both marine and freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael Guiry. Text was copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. (Sehere. By 2005, the database contained about 65,000 names. In 2013, AlgaeBase and the Flanders Marine Institute (VLIZ) signed an end-user license agreement regarding the Electronic Intellectual Property of AlgaeBase. This allows the World Register of Marine Species (WoRMS) to include taxonomic names of algae in WoRMS, thereby allowing WoRMS, as part of the Aphia database, to make its overview of all described marine species more complete. Synchronisation of the AlgaeBase data with Aphia and WoRMS was undertaken manually until March 2015, but this was very time-consuming, so an online application was developed to semi-automate the synchronisation, launching in 2015 in conju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anabaena
''Anabaena'' is a genus of filamentous cyanobacteria that exist as plankton. They are known for nitrogen-fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to local wildlife, as well as farm animals and pets. Production of these neurotoxins is assumed to be an input into its symbiotic relationships, protecting the plant from grazing pressure. A DNA sequencing project was undertaken in 1999, which mapped the complete genome of ''Anabaena'', which is 7.2 million base pairs long. The study focused on heterocysts, which convert nitrogen into ammonia. Certain species of ''Anabaena'' have been used on rice paddy fields, proving to be an effective natural fertilizer. Nitrogen fixation by ''Anabaena'' Under nitrogen-limiting conditions, vegetative cells differentiate into heterocysts at semiregular intervals along the filaments. Heterocyst c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbiosis
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. The organisms, each termed a symbiont, must be of different species. In 1879, Heinrich Anton de Bary defined it as "the living together of unlike organisms". The term was subject to a century-long debate about whether it should specifically denote mutualism, as in lichens. Biologists have now abandoned that restriction. Symbiosis can be obligatory, which means that one or more of the symbionts depend on each other for survival, or facultative (optional), when they can generally live independently. Symbiosis is also classified by physical attachment. When symbionts form a single body it is called conjunctive symbiosis, while all other arrangements are called disjunctive symbiosis."symbiosis." Dorland's Illustrated Medical Dictionary. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anabaena20151208152159
''Anabaena'' is a genus of filamentous cyanobacteria that exist as plankton. They are known for nitrogen-fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to local wildlife, as well as farm animals and pets. Production of these neurotoxins is assumed to be an input into its symbiotic relationships, protecting the plant from grazing pressure. A DNA sequencing project was undertaken in 1999, which mapped the complete genome of ''Anabaena'', which is 7.2 million base pairs long. The study focused on heterocysts, which convert nitrogen into ammonia. Certain species of ''Anabaena'' have been used on rice paddy fields, proving to be an effective natural fertilizer. Nitrogen fixation by ''Anabaena'' Under nitrogen-limiting conditions, vegetative cells differentiate into heterocysts at semiregular intervals along the filaments. Heterocyst cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nile Delta
The Nile Delta ( ar, دلتا النيل, or simply , is the delta formed in Lower Egypt where the Nile River spreads out and drains into the Mediterranean Sea. It is one of the world's largest river deltas—from Alexandria in the west to Port Said in the east, it covers of Mediterranean coastline and is a rich agricultural region. From north to south the delta is approximately in length. The Delta begins slightly down-river from Cairo. Geography From north to south, the delta is approximately in length. From west to east, it covers some of coastline. The delta is sometimes divided into sections, with the Nile dividing into two main distributaries, the Damietta and the Rosetta, flowing into the Mediterranean at port cities with the same name. In the past, the delta had several distributaries, but these have been lost due to flood control, silting and changing relief. One such defunct distributary is Wadi Tumilat. The Suez Canal is east of the delta and enters the coa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
