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Layia Discoidea
''Layia discoidea'' is a rare species of flowering plant in the family Asteraceae known by the common name rayless tidytips, or rayless layia. Distribution ''Layia discoidea'' is a local serpentine endemic where it is known only from the Diablo Range in southern San Benito County and far western Fresno County. The known distribution of the species is the New Idria serpentine mass (BLM Clear Creek Management Area) and nearby Laguna Mountain, Hepsedam Peak, and Panther Peak serpentine masses. ''Layia discoidea'' is regarded as a strict serpentine endemic with several populations known (as of 2017) to occur on greywacke and chert outcrop and talus at the edge of the New Idria Serpentine Mass near Condon Peak, Sampson Peak, and Idria Reservoir. Typical habitat of the species is serpentine rock outcrop, serpentine talus, and serpentine stream terraces where it grows in full sun with little to no competition from other plant species. The shale and chert outcrop habitat that a few ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David D
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". was, according to the Hebrew Bible, the third king of the United Kingdom of Israel. In the Books of Samuel, he is described as a young shepherd and harpist who gains fame by slaying Goliath, a champion of the Philistines, in southern Canaan. David becomes a favourite of Saul, the first king of Israel; he also forges a notably close friendship with Jonathan, a son of Saul. However, under the paranoia that David is seeking to usurp the throne, Saul attempts to kill David, forcing the latter to go into hiding and effectively operate as a fugitive for several years. After Saul and Jonathan are both killed in battle against the Philistines, a 30-year-old David is anointed king over all of Israel and Judah. Following his rise to power, David ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pappus (flower Structure)
In Asteraceae, the pappus is the modified calyx, the part of an individual floret, that surrounds the base of the corolla tube in flower. It functions as a wind-dispersal mechanism for the seeds. The term is sometimes used for similar structures in other plant families e.g. in certain genera of the Apocynaceae, although the pappus in Apocynaceae is not derived from the calyx of the flower. In Asteraceae, the pappus may be composed of bristles (sometimes feathery), awns, scales, or may be absent, and in some species, is too small to see without magnification. In genera such as ''Taraxacum'' or ''Eupatorium'', feathery bristles of the pappus function as a "parachute" which enables the seed to be carried by the wind. The name derives from the Ancient Greek word ''pappos'', Latin ''pappus'', meaning "old man", so used for a plant (assumed to be an ''Erigeron'' species) having bristles and also for the woolly, hairy seed of certain plants. The pappus of the dandelion plays a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Of The California Chaparral And Woodlands
Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena. The word ''nature'' is borrowed from the Old French ''nature'' and is derived from the Latin word ''natura'', or "essential qualities, innate disposition", and in ancient times, literally meant "birth". In ancient philosophy, ''natura'' is mostly used as the Latin translation of the Greek word ''physis'' (φύσις), which originally related to the intrinsic characteristics of plants, animals, and other features of the world to develop of their own accord. The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Flora Of California
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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Layia
''Layia'' is a genus of flowering plants in the family Asteraceae known generally as tidy tips, native to western North America. Several are California Endemism, endemics. These are erect daisylike annual herbs with dark glandular stems. The Head (botany), flower heads usually contain white or yellow ray florets; some species have yellow florets tipped sharply in white which give the flowers their common name. The genus is named for naturalist George Tradescant Lay, who was one of the discoverers of ''Layia gaillardioides''. ; Species References External links CalFlora Database: ''Layia''— ''with species images and links''. Jepson Manual Treatment — ''Layia''USDA Plants Profile: ''Layia'' * Layia, Asteraceae genera Flora of North America {{Asteroideae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid (biology)
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution (journal)
''Evolution: International Journal of Organic Evolution'', is a monthly scientific journal that publishes significant new results of empirical or theoretical investigations concerning facts, processes, mechanics, or concepts of evolutionary phenomena and events. ''Evolution'' is published by the Society for the Study of Evolution. Its current editor-in-chief is Tracey Chapman. Former editors-in-chief The journal was founded soon after the Second World War. Its first editor was the evolutionary geneticist Ernst Mayr. * Ruth Geyer Shaw, July 2013 – 2017 * Daphne Fairbairn Daphne (; ; el, Δάφνη, , ), a minor figure in Greek mythology, is a naiad, a variety of female nymph associated with fountains, wells, springs, streams, brooks and other bodies of freshwater. There are several versions of the myth in whi ..., 2010- June 2013 References External linksOfficial website Evolutionary biology journals Publications established in 1947 Academic journals published by l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripatric Speciation
Peripatric speciation is a mode of speciation in which a new species is formed from an isolated peripheral population. Since peripatric speciation resembles allopatric speciation, in that populations are isolated and prevented from exchanging genes, it can often be difficult to distinguish between them. Nevertheless, the primary characteristic of peripatric speciation proposes that one of the populations is much smaller than the other. The terms peripatric and peripatry are often used in biogeography, referring to organisms whose ranges are closely adjacent but do not overlap, being separated where these organisms do not occur—for example on an oceanic island compared to the mainland. Such organisms are usually closely related (''e.g.'' sister species); their distribution being the result of peripatric speciation. The concept of peripatric speciation was first outlined by the evolutionary biologist Ernst Mayr in 1954.Ernst Mayr. (1954). Change of genetic environment and evolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allopatric Speciation
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Layia Glandulosa
''Layia glandulosa'' is a species of flowering plant in the family Asteraceae known by the common names whitedaisy tidytips and white layia. It is native to western North America south from central Washington (state) to Baja California and east to Utah and Arizona, where it is common in a number of habitat types. Description This is an annual herb producing an erect stem to a maximum height just over . The stem and foliage are dotted with dark glandular hairs and the plant is sometimes scented. The thin leaves are linear to oval-shaped, with the lower ones often lobed, approaching in maximum length. The flower head has a base of green, hairy, glandular phyllaries. The face is fringed with 3–14 (typically 5) broad, 3-lobed ray florets which are usually white, but sometimes yellow. The center contains yellow disc florets with yellow anthers. The fruit is a hairy achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not open at maturity). Achenes contain a single seed that nearly fills the pericarp, but does not adhere to it. In many species, what is called the "seed" is an achene, a fruit containing the seed. The seed-like appearance is owed to the hardening of the fruit wall (pericarp), which encloses the solitary seed so closely as to seem like a seed coat. Examples The fruits of buttercup, buckwheat, caraway, quinoa, amaranth, and cannabis are typical achenes. The achenes of the strawberry are sometimes mistaken for seeds. The strawberry is an accessory fruit with an aggregate of achenes on its outer surface, and what is eaten is accessory tissue. A rose produces an aggregate of achene fruits that are encompassed within an expanded hypanthium (aka f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteraceae
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. Most species of Asteraceae are annual, biennial, or perennial herbaceous plants, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates, and they are found on every continent but Antarctica. The primary common characteristic is the existence of sometimes hundreds of tiny individual florets which are held together by protective involucres in flower heads, or more technicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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