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Dahlia
''Dahlia'' ( , ) is a genus of bushy, tuberous, herbaceous perennial plants native to Mexico and Central America. Dahlias are members of the Asteraceae (synonym name: Compositae) family of dicotyledonous plants, its relatives include the sunflower, daisy, chrysanthemum, and zinnia. There are 49 species of dahlia, with flowers in almost every hue (except blue), with hybrids commonly grown as garden plants. Dahlias were known only to the Aztecs and other southern North American peoples until the Spanish conquest, after which the plants were brought to Europe. The tubers of some varieties are of medicinal and dietary value to humans because they contain inulin, a polymer of the fruit sugar, fructose. Description Dahlias are perennial plants with tuberous roots. They are not frost hardy, and require protection from frost if grown in regions with cold winters. While some have herbaceous stems, others have stems which lignify in the absence of secondary tissue and resprout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dahlia Pinnata
''Dahlia pinnata'' (''D.'' × ''pinnata'') is a species in the genus ''Dahlia'', family Asteraceae, with the common name garden dahlia. It is the type species of the genus and is widely cultivated. Description ''Dahlia pinnata'' is a perennial herbaceous plant with a rhizome and tuberous roots, reaching a height of , rarely 160 cm. The stem is erect, and branched only in the inflorescence. The leaves are usually simple, with leaflets that are ovate and long. The plant is slightly shaggy. Between July and October, atop stems 5 to 15 cm in length are two to eight flower heads, 6 to 10 cm in diameter. The eight florets have a length of 3 to 5 cm, are ovate and coloured pink to deep purple. Taxonomy Hansen and Hjerting in (1996) demonstrated that ''Dahlia pinnata'' should more properly be designated ''D. x pinnata''. ''D. x pinnata'' was shown to actually be a variant of '' D. sorensenii'' that had acquired hybrid qualities before it was introduced to Europe in the sixteenth c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perennial
In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also loosely used to distinguish plants with little or no woody growth (secondary growth in girth) from trees and shrubs, which are also technically ''perennials''. Notably, it is estimated that 94% of plant species fall under the category of perennials, underscoring the prevalence of plants with lifespans exceeding two years in the botanical world. Perennials (especially small flowering plants) that grow and bloom over the spring and summer, die back every autumn and winter, and then return in the spring from their rootstock or other overwintering structure, are known as herbaceous perennials. However, depending on the rigours of the local climate (temperature, moisture, organic content in the soil, microorganisms), a plant that is a peren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dalea
''Dalea'' is a genus of flowering plants in the legume family, Fabaceae. Members of the genus are commonly known as prairie clover or indigo bush. Its name honors English apothecary Samuel Dale (physician), Samuel Dale (1659–1739). They are native to the Western hemisphere, where they are distributed from Canada to Argentina. Nearly half of the known species are endemism, endemic to Mexico. Two species of ''Dalea'' (''Dalea ornata'' and ''Dalea searlsiae'') have been considered for rangeland Environmental restoration, restoration. Species ''Dalea'' comprises the following species: * ''Dalea abietifolia'' (Rydb.) Bullock * ''Dalea acracarpica'' Barneby * ''Dalea adenopoda'' (Rydb.) Isely—Tampa prairie clover * ''Dalea aenigma'' Barneby * ''Dalea albiflora'' A. Gray—whiteflower prairie clover * ''Dalea analiliana'' Spellenb. * ''Dalea ananassa'' Barneby * ''Dalea antana'' J.F. Macbr. * ''Dalea arenicola'' (Wemple) B.L. Turner * ''Dalea aurea'' C. Fras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteraceae
Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. 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 taxon, extant species in each family is unknown. The Asteraceae were first described in the year 1740 and given the original name Composita, Compositae. The family is commonly known as the aster, Daisy (flower), daisy, composite, or sunflower family. Most species of Asteraceae are herbaceous plants, and may be Annual plant, annual, Biennial plant, biennial, or Perennial plant, perennial, 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 climate, hot desert and cold or hot Semi-arid climate, semi-desert climates, and they are found on ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antonio José Cavanilles
Antonio José Cavanilles (16 January 1745 – 5 May 1804) was a leading Spanish taxonomic botanist, artist and one of the most important figures in the 18th century period of Enlightenment in Spain. Cavanilles is most famous for his 2-volume book on Spanish flora, published in 1795 and titled ‘Observations on the Natural History, Geography and Agriculture of the Kingdom of Valencia’.He named many plants, particularly from Oceania. He named at least 100 genera, about 54 of which were still used in 2004, including ''Dahlia'', '' Calycera'', '' Cobaea'', '' Galphimia'', and '' Oleandra''. Biography Cavanilles was born in Valencia. He lived in Paris from 1777 to 1781, where he followed careers as a clergyman and a botanist, thanks to André Thouin and Antoine Laurent de Jussieu. He was one of the first Spanish scientists to use the classification method invented by Carl Linnaeus. Early life and education Antonio José Cavanilles was born on January 16, 1745, in Valenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or butterflies; birds, and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants. Self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid (biology), hybrid offspring in nature and in plant breeding work. In angiosperms, after the pollen grain (gametophyte) has landed on the stigma (botany), stigma, it germinates and develops a pollen tube which grows down the style (botany), style until it reaches an ovary (botany), ovary. Its two gametes travel down ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek Dark Ages, Dark Ages (), the Archaic Greece, Archaic or Homeric Greek, Homeric period (), and the Classical Greece, Classical period (). Ancient Greek was the language of Homer and of fifth-century Athens, fifth-century Athenian historians, playwrights, and Ancient Greek philosophy, philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Homeric Greek, Epic and Classical periods of the language, which are the best-attested periods and considered most typical of Ancient Greek. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aster (genus)
''Aster'' is a genus of perennial flowering plants in the family Asteraceae. Its circumscription has been narrowed, and it now encompasses around 170 species, all but one of which are restricted to Eurasia; many species formerly in ''Aster'' are now in other genera of the tribe Astereae. '' Aster amellus'' is the type species of the genus and the family Asteraceae. The name ''Aster'' comes from the Ancient Greek word (), meaning 'star', referring to the shape of the flower head. Many species and a variety of hybrids and varieties are popular as garden plants because of their attractive and colourful flowers. 'Aster' species are used as food plants by the larvae of a number of Lepidoptera species—see list of Lepidoptera that feed on ''Aster''. Asters can grow in all hardiness zones. Circumscription The genus ''Aster'' once contained nearly 600 species in Eurasia and North America, but after morphologic and molecular research on the genus during the 1990s, it was decide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spanish Conquest Of The Aztec Empire
The Spanish conquest of the Aztec Empire was a pivotal event in the history of the Americas, marked by the collision of the Aztec Triple Alliance and the Spanish Empire. Taking place between 1519 and 1521, this event saw the Spanish conquistador Hernán Cortés, and his small army of European soldiers and numerous indigenous allies, overthrowing one of the most powerful empires in Mesoamerica. Led by the Aztec ruler Moctezuma II, the Aztec Empire had established dominance over central Mexico through military conquest and intricate alliances. Because the Aztec Empire ruled via hegemonic control by maintaining local leadership and relying on the psychological perception of Aztec power — backed by military force — the Aztecs normally kept subordinate rulers compliant. This was an inherently unstable system of governance, as this situation could change with any alteration in the status quo. A combination of factors including superior weaponry, strategic alliances with oppresse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octoploid
Polyploidy is a condition in which the cells of an organism have more than two paired sets of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs of homologous chromosomes. 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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Homology
Sequence homology is the homology (biology), biological homology between DNA sequence, DNA, RNA sequence, RNA, or Protein primary structure, protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speciation event (orthologs), or a Gene duplication, duplication event (paralogs), or else a Horizontal gene transfer, horizontal (or lateral) gene transfer event (xenologs). Homology among DNA, RNA, or proteins is typically inferred from their nucleotide or amino acid sequence similarity. Significant similarity is strong evidence that two sequences are related by evolutionary changes from a common ancestral sequence. Sequence alignment, Alignments of multiple sequences are used to indicate which regions of each sequence are homologous. Identity, similarity, and conservation The term "percent homology" is often used to mean "sequence similarity”, that is the percen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudanthium
A pseudanthium (; : pseudanthia) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers, or capitula, which are special types of inflorescences in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The real flowers (the florets) are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large (as in the heads of some varieties of sunflower). Pseudanthia are characteristic of the daisy and sunflower family (biology), family (Asteraceae), whose flowers are differentiated into ray flowers and disk flowers, unique to this family. The disk flowers in the center of the pseudanthium are actinomorphic and the corolla (flower), corolla is fused into a tube. Flowers on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
