|
Thlaspi Californicum
''Thlaspi californicum'' is a rare species of flowering plant in the family Brassicaceae known by the common name Kneeland Prairie penny-cress. It is endemic to California, where it is known from only one stretch of grassland in Humboldt County. It is threatened by development. It is a federally listed endangered species of the United States. The taxonomy of this species is uncertain. Authors call it ''Thlaspi californicum'',''Thlaspi californicum''. ''Jepson Manual Treatment''. Retrieved August 17, 2011.''Thlaspi californicum''. ''The Nature Conservancy''. Retrieved August 17, 2011. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sereno Watson
Sereno Watson (December 1, 1826 in East Windsor Hill, Connecticut – March 9, 1892 in Cambridge, Massachusetts) was an American botanist. Graduating from Yale in 1847 in Biology, he drifted through various occupations until, in California, he joined the Clarence King Expedition and eventually became its expedition botanist. Appointed by Asa Gray as assistant in the Gray Herbarium of Harvard University in 1873, he later became its curator, a position he maintained until his death. Watson was elected a Fellow of the American Academy of Arts and Sciences in 1874, and a member of the National Academy of Sciences in 1889. Works * ''Botany'', in ''Report of the geological exploration of the 40th parallel made ... by Clarence King'', 1871 * * Publications by and about S. Watsoon WorldCat References External linksBiographical sketch at the Gray Herbarium site [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloning
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, cloning is the process of creating cloned organisms (copies) of Cell (biology), cells and of DNA fragments (molecular cloning). Etymology Coined by Herbert J. Webber, the term clone derives from the Ancient Greek word (), ''twig'', which is the process whereby a new plant is created from a twig. In botany, the term ''lusus'' was used. In horticulture, the spelling ''clon'' was used until the early twentieth century; the final ''e'' came into use to indicate the vowel is a "long o" instead of a "short o". Since the term entered the popular lexicon in a more general context, the spelling ''clone'' has been used exclusively. Natural cloning Cloning is a natural form of reproduction that has allowed life forms to spread for hundreds of millio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species. More specifically, habitat fragmentation is a process by which large and contiguous habitats get divided into smaller, isolated patches of habitats. Definition The term habitat fragmentation includes five discrete phenomena: * Reduction in the total area of the habitat * Decrease of the interior: edge ratio * Isolation of one habitat fragment from other areas of habitat * Breaking up of one patch of habitat into several smaller patches * Decrease in the average size of each patch of habitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helitack
Helitack crews are teams of wildland firefighters who are transported by helicopter to wildfires. Helicopters provide rapid transport, enabling helitack crews to quickly respond and assess a wildfire situation. Helitack crews may land near a wildfire or, if equipped and trained, rappel from a hovering helicopter. Once on the ground, crews build firelines using hand tools, chainsaws, and other firefighting tools. They often remain overnight in remote locations. After they have completed their assignment, crew members may pack up to 120 pounds of equipment over difficult terrain to reach a pick-up point. Rappellers often prepare helispots (helicopter landing zones) that provide better access to a fire. Helicopter crew members may also perform other duties such as tree falling, firing operations, and managing helibases. Terminology Helitack The term ''helitack'' first appeared in a 1956 ''Los Angeles Times'' article, which described the "first of a series of tests—tabbed the Hel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentine Soil
Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially antigorite, lizardite, and chrysotile or white asbestos, all of which are commonly found in ultramafic rocks. The term "serpentine" is commonly used to refer to both the soil type and the mineral group which forms its parent materials. Serpentine soils exhibit distinct chemical and physical properties and are generally regarded as poor soils for agriculture. The soil is often reddish, brown, or gray in color due to its high iron and low organic content. Geologically, areas with serpentine bedrock are characteristically steep, rocky, and vulnerable to erosion, which causes many serpentine soils to be rather shallow. The shallow soils and sparse vegetation lead to elevated soil temperatures and dry conditions. Due to their ultramafic origin, ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by soil and vegetation and cannot be seen or examined closely. However, in places where the overlying cover is removed through erosion or tectonic uplift, the rock may be exposed, or ''crop out''. Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides, mountain ridges and tops, river banks, and tectonically active areas. In Finland, glacial erosion during the last glacial maximum (ca. 11000 BC), followed by scouring by sea waves, followed by isostatic uplift has produced many smooth coastal and littoral outcrops. Bedrock and superficial deposits may also be exposed at the Earth's surface due to human excavations such as quarrying and build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentine Group
Serpentine subgroup (part of the kaolinite-serpentine group in the category of phyllosilicates) are greenish, brownish, or spotted minerals commonly found in serpentinite. They are used as a source of magnesium and asbestos, and as decorative stone. The name comes from the greenish colour and smooth or scaly appearance from the Latin , meaning "serpent rock". Serpentine subgroup is a set of common rock-forming hydrous magnesium iron phyllosilicate () minerals, resulting from the metamorphism of the minerals that are contained in mafic to ultramafic rocks. They may contain minor amounts of other elements including chromium, manganese, cobalt or nickel. In mineralogy and gemology, serpentine may refer to any of the 20 varieties belonging to the serpentine subgroup. Owing to admixture, these varieties are not always easy to individualize, and distinctions are not usually made. There are three important mineral polymorphs of serpentine: antigorite, lizardite and chrysotile. Serpen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eureka, California
Eureka (Wiyot: ''Jaroujiji'', Hupa: ''do'-wi-lotl-ding'', Karuk: ''uuth'') is the principal city and county seat of Humboldt County in the Redwood Empire region of California. The city is located on U.S. Route 101 on the shores of Humboldt Bay, north of San Francisco and south of the Oregon border. At the 2010 census, the population of the city was 27,191, and the population of Greater Eureka was 45,034. Eureka is the largest coastal city between San Francisco and Portland, Oregon, and the westernmost city of more than 25,000 residents in the 48 contiguous states.Eureka (city), California , State & County QuickFacts, January 10, 2013, note: in data set The proximity to the sea causes the city to have an extremely maritime clim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kneeland Airport
Kneeland Airport is a public airport operated by Humboldt County southeast of Eureka, California. Located on a mountain ridge at over above sea level, this airfield is used by general aviation aircraft, which sometimes seek an alternate airport when nearby low-lying airports are under fog. The airport has a California Dept. of Forestry (CDF) Helitack Station. Kneeland Airport is also used as an excellent sky watching location for the Humboldt Astronomers club. Facilities Kneeland Airport covers . Its one runway, 15/33, is and is asphalt paved. Ecology The airport bisects the only known population of the Kneeland Prairie pennycress (''Thlaspi californicum''), a federally listed endangered plant species.USFWS''Thlaspi californicum'' Five-year Review.June 2006. Other local airports * Arcata-Eureka Airport * Eureka Municipal Airport * Murray Field - in Eureka Eureka (often abbreviated as E!, or Σ!) is an intergovernmental organisation for research and developme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetative Reproduction
Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures, which are sometimes called vegetative propagules. Many plants naturally reproduce this way, but it can also be induced artificially. Horticulturists have developed asexual propagation techniques that use vegetative propagules to replicate plants. Success rates and difficulty of propagation vary greatly. Monocotyledons typically lack a vascular cambium, making them more challenging to propagate. Background Plant propagation is the process of plant reproduction of a species or cultivar, and it can be sexual or asexual. It can happen through the use of vegetative parts of the plants, such as leaves, stems, and roots to produce new plants or through growth from specialized vegetative plant parts. While m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brassicaceae
Brassicaceae () or (the older) Cruciferae () is a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous plants, while some are shrubs. The leaves are simple (although are sometimes deeply incised), lack stipules, and appear alternately on stems or in rosettes. The inflorescences are terminal and lack bracts. The flowers have four free sepals, four free alternating petals, two shorter free stamens and four longer free stamens. The fruit has seeds in rows, divided by a thin wall (or septum). The family contains 372 genera and 4,060 accepted species. The largest genera are ''Draba'' (440 species), ''Erysimum'' (261 species), ''Lepidium'' (234 species), ''Cardamine'' (233 species), and ''Alyssum'' (207 species). The family contains the cruciferous vegetables, including species such as ''Brassica oleracea'' (cultivated as cabbage, kale, cauliflower, broccoli and collards), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silique
A silique or siliqua (plural ''siliques'' or ''siliquae'') is a type of fruit (seed capsule) having two fused carpels with the length being more than three times the width. When the length is less than three times the width of the dried fruit it is referred to as a silicle. The outer walls of the ovary (the ''valves'') usually separate when ripe, then being named ''dehiscent'', and leaving a persistent partition (the ''replum''). ''Siliques'' are present in many members of the mustard family, Brassicaceae, but some species have ''silicles'' instead. Some species closely related to plants with true ''siliques'' have fruits with a similar structure that do not open when ripe; these are usually called ''indehiscent siliques'' (compare dehiscence). Lunaria annua MHNT.BOT.2004.0.779.jpg, Silicles of ''Lunaria annua'' – MHNT Capsella bursa-pastoris Sturm23.jpg, ''Capsella bursa-pastoris'' with silicles Raphanus sativus 004.jpg, Indehiscent siliques of radish ''Raphanus sativus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
