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Streptanthus Howellii
''Streptanthus howellii'' is an uncommon species of flowering plant in the mustard family known by the common name Howell's jewelflower. It is endemic to the Klamath Mountains of southern Oregon and northern California. It grows in mountain forests on serpentine soils. It is a perennial herb producing a hairless, often waxy-textured stem up to 70 or 80 centimeters in maximum length. It is generally unbranched. The ephemeral basal leaves have fleshy oval blades with smooth or toothed edges, borne on petioles. Leaves farther up the stem are similar but smaller and narrower, with shorter petioles or none. They do not clasp the stem. Flowers occur at intervals along the upper stem. Each has a calyx of purple sepals under a centimeter long with purple-tipped yellow petals emerging from the tip. The fruit is a thin, smooth, curved silique up to 12 centimeters long. This rare plant is threatened by wildfire suppression; it would be more common if its habitat were allowed its natural fir ... [...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] |
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] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klamath Mountains
The Klamath Mountains are a rugged and lightly populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast Ranges, the Klamath Mountains have a varied geology, with substantial areas of serpentinite and marble, and a climate characterized by moderately cold winters with very heavy snowfall and warm, very dry summers with limited rainfall, especially in the south. As a consequence of the geology and soil types, the mountains harbor several endemic or near-endemic trees, forming one of the largest collections of conifers in the world. The mountains are also home to a diverse array of fish and animal species, including black bears, large cats, owls, eagles, and several species of Pacific salmon. Millions of acres in the mountains are managed by the United States Forest Service. The northernmost and largest sub-range of the Klamath Mountains are the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of its eastern boundary with Idaho. The 42nd parallel north, 42° north parallel delineates the southern boundary with California and Nevada. Oregon has been home to many Indigenous peoples of the Americas, indigenous nations for thousands of years. The first European traders, explorers, and settlers began exploring what is now Oregon's Pacific coast in the early-mid 16th century. As early as 1564, the Spanish expeditions to the Pacific Northwest, Spanish began sending vessels northeast from the Philippines, riding the Kuroshio Current in a sweeping circular route across the northern part of the Pacific. In 1592, Juan de Fuca undertook detailed mapping and studies of ocean currents in the Pacific Northwest, including the Oregon coast as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territories of the United States by population, most populous U.S. state and the List of U.S. states and territories by area, 3rd largest by area. It is also the most populated Administrative division, subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous Statistical area (United States), urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento, California, Sacramento is the state's capital, while Los Angeles is the List of largest California cities by population, most populous city in the state and the List of United States cities by population, ... [...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] |
Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves with a petiole are said to be petiolate, while leaves lacking a petiole are called sessile or apetiolate. Description The petiole is a stalk that attaches a leaf to the plant stem. In petiolate leaves, the leaf stalk may be long, as in the leaves of celery and rhubarb, or short. When completely absent, the blade attaches directly to the stem and is said to be sessile. Subpetiolate leaves have an extremely short petiole, and may appear sessile. The broomrape family Orobanchaceae is an example of a family in which the leaves are always sessile. In some other plant groups, such as the speedwell genus '' Veronica'', petiolate and sessile leaves may occur in different species. In the grasses (Poaceae), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined by Noël Martin Joseph de Necker in 1790, and derived . Collectively the sepals are called the calyx (plural calyces), the outermost whorl of parts that form a flower. The word ''calyx'' was adopted from the Latin ,Jackson, Benjamin, Daydon; A Glossary of Botanic Terms with their Derivation and Accent; Published by Gerald Duckworth & Co. London, 4th ed 1928 not to be confused with 'cup, goblet'. ''Calyx'' is derived from Greek 'bud, calyx, husk, wrapping' ( Sanskrit 'bud'), while is derived from Greek 'cup, goblet', and the words have been used interchangeably in botanical Latin. After flowering, most plants have no more use for the calyx which withers or becomes vestigial. Some plants retain a thorny calyx, either dried or live, as ... [...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] |
Wildfire Suppression
Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts in wild land areas require different techniques, equipment, and training from the more familiar structure fire fighting found in populated areas. Working in conjunction with specially designed aerial firefighting aircraft, these wildfire-trained crews suppress flames, construct fire lines, and extinguish flames and areas of heat to protect resources and natural wilderness. Wildfire suppression also addresses the issues of the wildland–urban interface, where populated areas border with wild land areas. In the United States and other countries, aggressive wildfire suppression aimed at minimizing fire has contributed to accumulation of fuel loads, increasing the risk of large, catastrophic fires. History Australia Wildland fire, known in Australia as bush fire, has played a major role in Australia due to arid conditions. Notable fire services tasked with wildfire suppres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Regime
A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes the spatial and temporal patterns and ecosystem impacts of fire on the landscape, and provides an integrative approach to identifying the impacts of fire at an ecosystem or landscape level.Morgan, Penelope; Hardy; Swetnam; Rollins; Long (1999)"Mapping fire regimes across time and space: Understanding coarse and fine-scale fire patterns"(PDF). ''International Journal of Wildland Fire''. 10: 329–342 – via Google Scholar. If fires are too frequent, plants may be killed before they have matured, or before they have set sufficient seed to ensure population recovery. If fires are too infrequent, plants may mature, senesce, and die without ever releasing their seed. Fire regimes can change with the spatial and temporal variations in topography, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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