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Xanthidium Tumidum
''Xanthidium'' is a genus of green algae, specifically of the Desmidiaceae. The name ''Xanthidium'' is a diminutive of ''Xanthium'', and presumably refers to its spines, reminiscent of the prickly fruits of ''Xanthium. Description ''Xanthidium'' exists as symmetrical single cells. Cells are deeply constricted, forming two halves called semicells; they are rectangular, rounded, or polygonal in front view, flattened. The angles are usually drawn out into spines, which are typically paired and sometimes branched. Semicells often have a protuberance or additional spine in the center of the semicell. Cells have two or many axile chloroplasts which fill the cell. A notable exception is the species '' Xanthidium tumidum'', formerly placed in the genus ''Staurastrum ''Staurastrum'' is a large genus of desmids (Desmidiaceae), a group of green algae closely related to the land plants (Embryophyta). Members of this genus are microscopic and found in freshwater habitats around the world. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Gottfried Ehrenberg
Christian Gottfried Ehrenberg (19 April 1795 – 27 June 1876) was a German Natural history, naturalist, zoologist, Botany, botanist, comparative anatomist, geologist, and microscopy, microscopist. He is considered to be one of the most famous and productive scientists of his time. Early collections The son of a judge, Christian Gottfried Ehrenberg was born in Delitzsch, near Leipzig. He first studied theology at the University of Leipzig, then medicine and natural sciences in Humboldt University of Berlin, Berlin and became a friend of the famous List of explorers, explorer Alexander von Humboldt. In 1818, he completed his doctoral dissertation on fungi, ''Sylvae mycologicae Berolinenses.'' In 1820–1825, on a scientific expedition to the Middle East with his friend Wilhelm Hemprich, he collected thousands of specimens of plants and animals. He investigated parts of Egypt, the Libyan Desert, the Nile, Nile valley and the northern coasts of the Red Sea, where he made a special ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthidium Trilobum
''Xanthidium'' is a genus of green algae, specifically of the Desmidiaceae. The name ''Xanthidium'' is a diminutive of ''Xanthium'', and presumably refers to its spines, reminiscent of the prickly fruits of ''Xanthium. Description ''Xanthidium'' exists as symmetrical single cells. Cells are deeply constricted, forming two halves called semicells; they are rectangular, rounded, or polygonal in front view, flattened. The angles are usually drawn out into spines, which are typically paired and sometimes branched. Semicells often have a protuberance or additional spine in the center of the semicell. Cells have two or many axile chloroplasts which fill the cell. A notable exception is the species '' Xanthidium tumidum'', formerly placed in the genus ''Staurastrum ''Staurastrum'' is a large genus of desmids (Desmidiaceae), a group of green algae closely related to the land plants (Embryophyta). Members of this genus are microscopic and found in freshwater habitats around the world. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the Radiant energy, energy from sunlight and convert it to chemical energy and release oxygen. The chemical energy created is then used to make sugar and other organic molecules from carbon dioxide in a process called the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in some unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. Chloroplasts are highly dynamic—they circulate and are moved around within cells. Their behavior is strongly influenced by environmental factors like light color and intensity. Chloroplasts cannot be made anew by the plant cell and must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthium
''Xanthium'' (cocklebur) is a genus of flowering plants in the tribe Heliantheae within the family Asteraceae, native to the Americas and eastern Asia and some parts of south Asia. Description Cockleburs are coarse, herbaceous annual plants growing to tall. The leaves are spirally arranged, with deeply toothed margins. Some species, notably ''Xanthium spinosum'', are also very thorny with long, slender Thorns, spines, and prickles, spines at the leaf bases. The flower heads are of two types; One, in short terminal branches, produces only pollen. The other, in clusters in the axils of the leaves, produces seed. Unlike many other members of the family Asteraceae, whose seeds are airborne with a plume of silky hairs resembling miniature parachutes, cocklebur seeds are produced in a hard, spiny, globose or oval double-chambered, single-seeded bur long. It is covered with stiff, hooked spines, which stick to fur and clothing and can be quite difficult to detach. These burs are carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diminutive
A diminutive is a word obtained by modifying a root word to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment, and sometimes to belittle something or someone. A ( abbreviated ) is a word-formation device used to express such meanings. A is a diminutive form with two diminutive suffixes rather than one. Purpose Diminutives are often employed as nicknames and pet names when speaking to small children and when expressing extreme tenderness and intimacy to an adult. The opposite of the diminutive form is the augmentative. In some contexts, diminutives are also employed in a pejorative sense to denote that someone or something is weak or childish. For example, one of the last Western Roman emperors was Romulus Augustus, but his name was diminutivized to "Romulus Augustulus" to express his powerlessness. Formation In many languages, diminutives are word forms that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Center For Biotechnology Information
The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is located in Bethesda, Maryland, and was founded in 1988 through legislation sponsored by US Congressman Claude Pepper. The NCBI houses a series of databases relevant to biotechnology and biomedicine and is an important resource for bioinformatics tools and services. Major databases include GenBank for DNA sequences and PubMed, a bibliographic database for biomedical literature. Other databases include the NCBI Epigenomics database. All these databases are available online through the Entrez search engine. NCBI was directed by David Lipman, one of the original authors of the BLAST sequence alignment program and a widely respected figure in bioinformatics. GenBank NCBI had responsibility for making available the GenBank DNA seque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmidiaceae
The Desmidiaceae are one of four family (biology), families of Charophyta, charophyte green algae in the order (biology), order Desmidiales (desmids).See the National Center for Biotechnology Information, NCBI]webpage on Desmidiaceae Data extracted from the Desmids in the family Desmidiaceae consist of single-celled (sometimes filamentous or colonial), microscopic green algae. Because they are highly symmetrical, attractive, and come in a diversity of forms, they are popular subjects for microscopy, microscopists, both amateur and professional. Within the desmids (Desmidiales), Desmidiaceae contains tens of genera and thousands of species, making it by far the largest family. Desmidiaceae includes some of the largest and most complex desmid genera, such as ''Micrasterias'', ''Cosmarium'', ''Staurastrum'', and ''Euastrum''. Description Desmids are single-celled (sometimes filamentous or colonial) algae, which are generally constricted in the middle, having two identical halves c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep within the charophytes as a sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid (spherical), and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae, many of which live most of their lives as single cells, while other species form coenobia (colonies), long filaments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus (biology)
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demonstrate both monophyly and validity as a separate lineage). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthidium Superbum
''Xanthidium'' is a genus of green algae, specifically of the Desmidiaceae. The name ''Xanthidium'' is a diminutive of ''Xanthium'', and presumably refers to its spines, reminiscent of the prickly fruits of ''Xanthium. Description ''Xanthidium'' exists as symmetrical single cells. Cells are deeply constricted, forming two halves called semicells; they are rectangular, rounded, or polygonal in front view, flattened. The angles are usually drawn out into spines, which are typically paired and sometimes branched. Semicells often have a protuberance or additional spine in the center of the semicell. Cells have two or many axile chloroplasts which fill the cell. A notable exception is the species ''Xanthidium tumidum'', formerly placed in the genus ''Staurastrum ''Staurastrum'' is a large genus of desmids (Desmidiaceae), a group of green algae closely related to the land plants (Embryophyta). Members of this genus are microscopic and found in freshwater habitats around the world. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Ralfs
John Ralfs (13 September 1807 – 14 July 1890) was an English botanist. Born in Millbrook, near Southampton, he was the second son of Samuel Ralfs, a yeoman of an old family in Hampshire. He has been commemorated in the names of many plant groups and taxa at many levels. Early life and education Ralfs's father died at Mudeford near Christchurch before John was a year old, and the children (two sons and two daughters) were brought up at Southampton by their mother. After being educated privately he was articled to his uncle, a surgeon of Brentford, with whom he lived for two years and a half. For two years he was a pupil at Winchester Hospital, and in 1832 he passed his final examination, being specially recommended by the examiners for his knowledge of botany. For some time he practised in partnership with another surgeon at Shoreditch, and he is also said to have practised at Towcester. At Torquay, where he moved on account of lung disease (probably tubercular in origin), he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
