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Juncus Dudleyi
''Juncus dudleyi'' is a widespread species of rush (genus ''Juncus''), native to North America, and introduced to northern South America, Japan, Great Britain and central Europe. Its diploid chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ... number is 2n=80. References dudleyi Flora of North America Plants described in 1900 {{Poales-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl McKay Wiegand
Karl McKay Wiegand (June 2, 1873 – March 12, 1942) was an American botanist who headed the Department of Botany at Cornell University for 28 years. He was a member of the Botanical Society of America The Botanical Society of America (BSA) represents professional and amateur botanists, researchers, educators and students in over 80 countries of the world. It functions as a United States nonprofit 501(c)(3) membership society. History The soci ... and served as its president in 1939. References External links * 1873 births 1942 deaths Cornell University faculty 20th-century American botanists {{US-botanist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juncus
''Juncus'' is a genus of monocotyledonous flowering plants, commonly known as rushes. It is the largest genus in the family Juncaceae, containing around 300 species. Description Rushes of the genus ''Juncus'' are herbaceous plants that superficially resemble grasses or sedges. They have historically received little attention from botanists; in his 1819 monograph, James Ebenezer Bicheno described the genus as "obscure and uninviting". The form of the flower differentiates rushes from grasses or sedges. The flowers of ''Juncus'' comprise five whorls of floral parts: three sepals, three petals (or, taken together, six tepals), two to six stamens (in two whorls) and a stigma with three lobes. The stems are round in cross-section, unlike those of sedges, which are typically somewhat triangular in cross-section. In ''Juncus'' section ''Juncotypus'' (formerly called ''Juncus'' subg. ''Genuini''), which contains some of the most widespread and familiar species, the leaves are reduced t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of North America
The ''Flora of North America North of Mexico'' (usually referred to as ''FNA'') is a multivolume work describing the native plants and naturalized plants of North America, including the United States, Canada, St. Pierre and Miquelon, and Greenland. It includes bryophytes and vascular plants. All taxa are described and included in dichotomous keys, distributions of all species and infraspecific taxa are mapped, and about 20% of species are illustrated with line drawings prepared specifically for FNA. It is expected to fill 30 volumes when completed and will be the first work to treat all of the known flora north of Mexico; in 2015 it was expected tha the series would conclude in 2017. Twenty-nine of the volumes have been published as of 2022. Soon after publication, the contents are made available online. FNA is a collaboration of about 1,000 authors, artists, reviewers, and editors from throughout the world. Reception The series has been praised for "the comprehensive treatme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
