|
Redwoods
Sequoioideae, popularly known as redwoods, is a subfamily of coniferous trees within the family Cupressaceae. It includes the largest and tallest trees in the world. Description The three redwood subfamily genera are '' Sequoia'' from coastal California and Oregon, ''Sequoiadendron'' from California's Sierra Nevada, and ''Metasequoia'' in China. The redwood species contains the largest and tallest trees in the world. These trees can live for thousands of years. Threats include logging, fire suppression, climate change, illegal marijuana cultivation, and burl poaching. Only two of the genera, ''Sequoia'' and ''Sequoiadendron'', are known for massive trees. Trees of ''Metasequoia'', from the single living species ''Metasequoia glyptostroboides'', are much smaller. Taxonomy and evolution Multiple studies of both morphological and molecular characters have strongly supported the assertion that the Sequoioideae are monophyletic. Most modern phylogenies place ''Sequoia'' as sis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequoia Sempervirens
''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal redwood, and California redwood. It is an evergreen, long-lived, monoecious tree living 1,200–2,200 years or more. This species includes the tallest living trees on Earth, reaching up to in height (without the roots) and up to in diameter at breast height. These trees are also among the oldest living things on Earth. Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated along much of coastal California (excluding southern California where rainfall is not sufficient) and the southwestern corner of coastal Oregon within the United States. The name sequoia sometimes refers to the subfamily Sequoioideae, which includes ''S. sempervirens'' along with ''Sequoiadendron'' (gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasequoia Glyptostroboides
''Metasequoia glyptostroboides'', the dawn redwood, is a fast-growing, endangered deciduous pinophyta, conifer. It is the sole living species of the genus ''Metasequoia'', one of three genera in the subfamily Sequoioideae of the family (botany), family Cupressaceae. It now survives only in wet lower slopes and montane river and stream valleys in the border region of Hubei and Hunan provinces and Chongqing municipality in south-central China, notably in Lichuan, Hubei, Lichuan county in Hubei. Although the shortest of the redwoods, it can grow to in height. In 1941, the genus ''Metasequoia'' was reported by paleobotanist Shigeru Miki as a widely distributed extinct genus based on fossils, before attracting considerable attention a few years later when small populations were found alive in central China. It is a particularly well-known example of a living fossil species. The tree faces considerable risks of extinction in its wild range due to deforestation, however it has been plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequoiadendron Giganteum
''Sequoiadendron giganteum'' (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, California big tree, Wellingtonia or simply big treea nickname also used by John Muir) is the sole living species in the genus ''Sequoiadendron'', and one of three species of coniferous trees known as Sequoioideae, redwoods, classified in the family Cupressaceae in the subfamily Sequoioideae, together with ''Sequoia sempervirens'' (coast redwood) and ''Metasequoia glyptostroboides'' (dawn redwood). Giant sequoia specimens are the most massive trees on Earth. The common use of the name ''sequoia'' usually refers to ''Sequoiadendron giganteum'', which occurs naturally only in groves on the western slopes of the Sierra Nevada (U.S.), Sierra Nevada mountain range of California. The giant sequoia is listed as an endangered species by the IUCN, with fewer than 80,000 trees remaining. Since its last assessment as an endangered species in 2011, it was estimated that another 13–19% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasequoia
''Metasequoia'', or dawn redwoods, is a genus of fast-growing deciduous trees, one of three species of pinophyta, conifers known as redwoods. The living species ''Metasequoia glyptostroboides'' is native to Lichuan, Hubei, Lichuan county in Hubei province, China. Although the shortest of the Sequoioideae, redwoods, it grows to at least in height. Local villagers refer to the original tree from which most others derive as ''Shuǐshān'' (水杉）, or "water fir", which is part of a local shrine. Since its rediscovery in 1944, the dawn redwood has become a popular ornamental, with examples found in various parks in a variety of countries. Together with ''Sequoia sempervirens'' (coast redwood) and ''Sequoiadendron giganteum'' (giant sequoia) of California, ''Metasequoia'' is classified in the Cupressaceae subfamily Sequoioideae. ''M. glyptostroboides'' is the only living species in its genus, but three fossil species are known. Sequoioideae and several other genera have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burl
A burl (American English) or burr (British English) is a tree growth in which the grain has grown in a deformed manner. It is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from dormant buds. Burl formation is typically a result of some form of stress such as an injury or a viral or fungal infection. Burls yield a very peculiar and highly figured wood sought after in woodworking, and some items may reach high prices on the wood market. Poaching of burl specimens and damaging the trees in the process poses a problem in some areas. Description A burl results from a tree undergoing some form of stress. It may be caused by an injury, virus or fungus. Most burls grow beneath the ground, attached to the roots as a type of malignancy that is generally not discovered until the tree dies or falls over. Such burls sometimes appear as groups of bulbous protrusions connected by a system of rope-like roots. Almost all burl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Superlative Trees
The world's superlative trees can be ranked by any factor. Records have been kept for trees with superlative height, trunk diameter or girth, canopy coverage, airspace volume, wood volume, estimated mass, and age. Tallest The heights of the tallest trees in the world have been the subject of considerable dispute and much exaggeration. Modern verified measurements with laser rangefinders or with tape drop measurements made by tree climbers (such as those carried out by canopy researchers), have shown that some older tree height measurement methods are often unreliable, sometimes producing exaggerations of 5% to 15% or more above the real height. Historical claims of trees growing to , and even , are now largely disregarded as unreliable, and attributed to human error. The following are the tallest reliably measured specimens from the top 10 species. This table shows only currently standing specimens: Tallest historically Despite the high heights attained by trees nowada ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequoia (genus)
''Sequoia'' is a genus of redwood coniferous trees in the subfamily Sequoioideae of the family Cupressaceae. The only extant species of the genus is ''Sequoia sempervirens'' in the Northern California coastal forests ecoregion of Northern California and Southwestern Oregon in the United States. The two other genera in the subfamily Sequoioideae, ''Sequoiadendron'' and ''Metasequoia'', are closely related to ''Sequoia''. It includes the tallest trees, as well as the heaviest, in the world. Several extinct species have been named from fossils, including '' Sequoia affinis ''(Western North America), '' Sequoia chinensis'' (no valid reference, identification uncertain) of China, ''Sequoia langsdorfii'' (reclassified as Metasequoia), '' Sequoia dakotensis'' (reclassified as Metasequoia) of South Dakota (Maastrichtian), and '' Sequoia magnifica'' (petrified wood from the Yellowstone National Park area). Etymology The name ''Sequoia'' was first published as a genus name by the Austr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinophyta
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews.Campbell, Reece, "Phylum Coniferophyta". Biology. 7th. 2005. Print. P. 595 As of 1998, the division Pinophyta was estimated to contain eight families, 68 genera, and 629 living species. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexaploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by meios ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferns
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes 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 leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled 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) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns. Ferns first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenies
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reticulate Evolution
Reticulate evolution, or network evolution is the origination of a lineage through the partial merging of two ancestor lineages, leading to relationships better described by a phylogenetic network than a bifurcating tree. Reticulate patterns can be found in the phylogenetic reconstructions of biodiversity lineages obtained by comparing the characteristics of organisms. Reticulation processes can potentially be convergent and divergent at the same time. Reticulate evolution indicates the lack of independence between two evolutionary lineages. Reticulation affects survival, fitness and speciation rates of species. Reticulate evolution can happen between lineages separated only for a short time, for example through hybrid speciation in a species complex. Nevertheless, it also takes place over larger evolutionary distances, as exemplified by the presence of organelles of bacterial origin in eukaryotic cells. Reticulation occurs at various levels:Perez, Julio E; Alfonsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
