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Symphyotrichum Defoliatum
''Symphyotrichum defoliatum'' (formerly ''Aster bernardinus'' and ''Aster defoliatus'') is a species of flowering plant in the family Asteraceae known by the common name San Bernardino aster. It is endemic to Southern California where it grows in grasslands and meadows, and it is of conservation concern. Description ''Symphyotrichum defoliatum'' is a perennial herbaceous plant growing from a long rhizome to a maximum height of . Leaves are widely lance-shaped to oblong and pointed, the largest ones near the base of the stem reaching up to long. The stem and leaves are roughly hairy. The inflorescence is an array of flower heads with 15–40 pale violet ray florets around a center of golden disk florets. The fruit is a hairy cypsela with a long pappus. Chromosomes ''Symphyotrichum defoliatum'' is an allopolyploid species likely derived from the backcrossing of '' S. falcatum'' (chromosome base number ''x'' = 5) with '' S. ascendens'' (base number ''x'' = 13), its hybrid de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Bonsall Parish
Samuel Bonsall Parish (1838–1928) was a California botanist and curator of the herbarium at Stanford University. A number of plants were named in his honor, including '' Allium parishii'', '' Atriplex parishii'', '' Boechera parishii'', '' Chaenactis parishii'', '' Cheilanthes parishii'', ''Delphinium parishii'' ssp. ''pallidum'', ''Delphinium parishii'' ssp. ''parishii'', ''Ericameria parishii'', '' Erigeron parishii'', ''Eriogonum parishii'', ''Eschscholzia parishii'', '' Euphorbia parishii'', '' Galium parishii'', '' Grusonia parishii'', '' Heuchera parishii'', ''Lycium parishii'', '' Malacothamnus parishii'', '' Mimulus parishii'', '' Orobanche parishii'' ssp. ''brachyloba'', '' Orobanche parishii'' ssp. ''parishii'', '' Perideridia parishii'', '' Phacelia parishii'', '' Plagiobothrys parishii'', '' Puccinellia parishii'', '' Silene parishii'', ''Solanum parishii'', '' Stipa parishii'', '' Symphoricarpos parishii'', ''Tauschia parishii'', ''Trichostema parishii ''Trichostema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbaceous Plant
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of the ''Shorter Oxford English Dictionary'' defines "herb" as: #"A plant whose stem does not become woody and persistent (as in a tree or shrub) but remains soft and succulent, and dies (completely or down to the root) after flowering"; #"A (freq. aromatic) plant used for flavouring or scent, in medicine, etc.". (See: Herb) The same dictionary defines "herbaceous" as: #"Of the nature of a herb; esp. not forming a woody stem but dying down to the root each year"; #"BOTANY Resembling a leaf in colour or texture. Opp. scarious". Botanical sources differ from each other on the definition of "herb". For instance, the Hunt Institute for Botanical Documentation includes the condition "when persisting over more than one growing season, the parts o ... [...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] |
Symphyotrichum Ascendens
''Symphyotrichum ascendens'' (formerly ''Aster ascendens'') is a species of flowering plant in the family Asteraceae known by the common names western aster, long-leaved aster, and Rocky Mountain aster. Blooming July–September, it is native to western North America and can be found at elevations of in several habitats. Description ''Symphyotrichum ascendens'' is a rhizomatous, perennial, and herbaceous plant growing a branching, erect stem to heights between . Leaves are widely lance-shaped to oblong and pointed, the largest ones near the base of the stem reaching up to long. The stem and leaves are roughly hairy in places. The inflorescence is an array of many flower heads with many narrow violet to nearly white ray florets around a center of golden disc florets that open July–September. The fruit is a hairy cypsela with a long pappus. ''S. ascendens'' is similar to ''Symphyotrichum chilense'', which has smaller flower heads. Chromosomes ''Symphyotrichum asc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symphyotrichum Falcatum
''Symphyotrichum falcatum'' (formerly ''Aster falcatus'') is a species of flowering plant in the family Asteraceae. Commonly called white prairie aster and western heath aster, it is native to a widespread area of central and western North America. Description White prairie aster blooms July–November depending on variety and location. It is colonial or cespitose and grows tall. It has hairy stems and hairy, grayish-green and firm entire leaves. On the outside of the flower heads of all members of the family Asteraceae are small specialized leaves called " phyllaries", and together they form the involucre that protects the individual flowers in the head before they open. The involucres of ''S. falcatum'' are campanulate (bell-shaped) and usually long. The outer phyllaries are spreading to reflexed (bent sharply backwards) and oblanceolate to spatulate in shape. The inner phyllaries are linear-lanceolate. They are in unequal rows, meaning they are staggered and do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backcrossing
Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, to achieve offspring with a genetic identity closer to that of the parent. It is used in horticulture, animal breeding, and production of gene knockout organisms. Backcrossed hybrids are sometimes described with acronym "BC"; for example, an F1 hybrid crossed with one of its parents (or a genetically similar individual) can be termed a BC1 hybrid, and a further cross of the BC1 hybrid to the same parent (or a genetically similar individual) produces a BC2 hybrid. Plants Advantages * If the recurrent parent is an elite genotype, at the end of the backcrossing programme, an elite genotype is recovered. * As no "new" recombination results, the elite combination is not lost. Disadvantages * It works poorly for quantitative traits. * It is more restricted for recessive traits. * In practice, sections of genome from the nonrecurrent parents are often still present and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allopolyploid
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 meiosi ... [...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] |
Cypsela (botany)
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] |
Disk Floret
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 technically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ray Floret
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 technically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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