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Nectar Spur
A nectar spur is a hollow extension of a part of a flower. The spur may arise from various parts of the flower: the sepals, petals, or hypanthium, and often contain tissues that secrete nectar Nectar, (nectaries). Nectar spurs are present in many clades across the Flowering plant, angiosperms, and are often cited as an example of List of examples of convergent evolution, convergent evolution. Taxonomic significance Spur length can be an important diagnostic character for taxonomy, useful in species identification. For example, Yadon's piperia can be distinguished from ''Platanthera elegans'', an extremely similar species in section ''Piperia'' (Orchidaceae), by the unusually short length of its spur. Ecology and evolution The presence of nectar spurs in a clade of plants is associated with evolutionary processes such as coevolution (two-sided evolution) and pollinator shifts (one-sided evolution). Like variations in floral tube length, variation in nectar spur length has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquilegia Formosa 1
''Aquilegia'' (common names: granny's bonnet, columbine) is a genus of about 60–70 species of perennial plants that are found in meadows, woodlands, and at higher altitudes throughout the Northern Hemisphere, known for the spurred petals Puzey, J.R., Gerbode, S.J., Hodges, S.A., Kramer, E.M., Mahadevan, L. (2011) Evolution of ''Aquilegia'' spur length diversity through changes in cell anisotropy. Proceedings of the Royal Society B. of their flowers. Etymology The genus name Aquilegia comes from the Latin “Aquila”, or “eagle”; this is in obvious reference to the spurred, “hook” shapes within the blooms, that many gardeners say resemble an eagle's talons. Description Perennial herbs, with woody, erect stock, roots forming thick rhizomes. The basal leaves are compound, 1–3 ternate, blades 3-lobed -partite, and lobes lobulate and obtuse. The cauline leaves are similar to the basal ones, while the upper ones are bract like. The hermaphrodite (bisexual) flowers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphinx Moth
The Sphingidae are a family of moths (Lepidoptera) called sphinx moths, also colloquially known as hawk moths, with many of their caterpillars known as “hornworms”; it includes about 1,450 species. It is best represented in the tropics, but species are found in every region.Scoble, Malcolm J. (1995): ''The Lepidoptera: Form, Function and Diversity'' (2nd edition). Oxford University Press & Natural History Museum London. They are moderate to large in size and are distinguished among moths for their agile and sustained flying ability, similar enough to that of hummingbirds as to be reliably mistaken for them. Their narrow wings and streamlined abdomens are adaptations for rapid flight. The family was named by French zoologist Pierre André Latreille in 1802. Some hawk moths, such as the hummingbird hawk-moth or the white-lined sphinx, hover in midair while they feed on nectar from flowers, so are sometimes mistaken for hummingbirds. This hovering capability is only known to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KNOX (genes)
The evolution of plants has resulted in a wide range of complexity, from the earliest algal mats, through multicellular marine and freshwater green algae, terrestrial bryophytes, lycopods and ferns, to the complex gymnosperms and angiosperms (flowering plants) of today. While many of the earliest groups continue to thrive, as exemplified by red algae, red and green algae in marine environments, more recently derived groups have displaced previously ecologically dominant ones; for example, the ascendance of flowering plants over gymnosperms in terrestrial environments. There is evidence that cyanobacteria and multicellular photosynthetic eukaryotes lived in freshwater communities on land as early as 1 billion years ago, and that communities of complex, multicellular photosynthesizing organisms existed on land in the late Precambrian, around . Evidence of the emergence of embryophyte land plants first occurs in the mid-Ordovician (~), and by the middle of the Devonian (~), many of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthologue
Sequence homology is the biological homology between DNA, RNA, or 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 duplication event (paralogs), or else a 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. 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 percentage of identical residues (''percent identity''), or the percentage of residues conserved with similar physicochemical properties (' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meristem
The meristem is a type of tissue found in plants. It consists of undifferentiated cells (meristematic cells) capable of cell division. Cells in the meristem can develop into all the other tissues and organs that occur in plants. These cells continue to divide until a time when they get differentiated and then lose the ability to divide. Differentiated plant cells generally cannot divide or produce cells of a different type. Meristematic cells are undifferentiated or incompletely differentiated. They are totipotent and capable of continued cell division. Division of meristematic cells provides new cells for expansion and differentiation of tissues and the initiation of new organs, providing the basic structure of the plant body. The cells are small, with no or small vacuoles and protoplasm fills the cell completely. The plastids (chloroplasts or chromoplasts), are undifferentiated, but are present in rudimentary form (proplastids). Meristematic cells are packed closely together wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homeobox
A homeobox is a DNA sequence, around 180 base pairs long, that regulates large-scale anatomical features in the early stages of embryonic development. For instance, mutations in a homeobox may change large-scale anatomical features of the full-grown organism. Homeoboxes are found within genes that are involved in the regulation of patterns of anatomical development (morphogenesis) in animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...s, fungus, fungi, plants, and numerous single cell eukaryotes. Homeobox genes encode homeodomain protein products that are transcription factors sharing a characteristic protein fold structure that binds DNA to regulate expression of target genes. Homeodomain proteins regulate gene expression and cell differentiation during early embryonic dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabidopsis Thaliana
''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small flowering plant native to Eurasia and Africa. ''A. thaliana'' is considered a weed; it is found along the shoulders of roads and in disturbed land. A winter annual with a relatively short lifecycle, ''A. thaliana'' is a popular model organism in plant biology and genetics. For a complex multicellular eukaryote, ''A. thaliana'' has a relatively small genome around 135 mega base pairs. It was the first plant to have its genome sequenced, and is a popular tool for understanding the molecular biology of many plant traits, including flower development and light sensing. Description ''Arabidopsis thaliana'' is an annual (rarely biennial) plant, usually growing to 20–25 cm tall. The leaves form a rosette at the base of the plant, with a few leaves also on the flowering stem. The basal leaves are green to slightly purplish in color, 1.5–5 cm long, and 2–10 mm broad, with an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antirrhinum Majus
''Antirrhinum majus'', the common snapdragon (often - especially in horticulture - simply "snapdragon"), is a species of flowering plant belonging to the genus ''Antirrhinum''. The plant was placed in the family Plantaginaceae following a revision of its prior classical family, Scrophulariaceae. The common name "snapdragon", originates from the flowers' reaction to having their throats squeezed, which causes the "mouth" of the flower to snap open like a dragon's mouth. It is widely used as an ornamental plant in borders and as a cut flower. It is perennial but usually cultivated as an annual plant. The species has been in culture since the 15th century. Taxonomy There are five subspecies: *''Antirrhinum majus'' subsp. ''majus''. Southern France, northeast Spain. *''Antirrhinum majus'' subsp. ''cirrhigerum'' (Ficalho) Franco. Southern Portugal, southwest Spain. *''Antirrhinum majus'' subsp. ''linkianum'' (Boiss. & Reut.) Rothm. Western Portugal (endemic). *''Antirrhinum maju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linaria
''Linaria'' is a genus of almost 200 species of flowering plants, one of several related groups commonly called toadflax. They are annuals and herbaceous perennials, and the largest genus in the Antirrhineae tribe of the plantain family Plantaginaceae. Taxonomy ''Linaria'' was traditionally placed in the family Scrophulariaceae. Phylogenetic analysis has now placed it in the vastly expanded family Plantaginaceae. Closely related genera include '' Nuttallanthus'' (American toadflaxes, recently split from ''Linaria''), ''Antirrhinum'' (snapdragons) and ''Cymbalaria'' (ivy-leaved toadflaxes). Cultivation Several ''Linaria'' species are cultivated as garden plants, and some are regarded as having a weedy habit. *Common toadflax or butter-and-eggs (''Linaria vulgaris''), a European species which is widely introduced elsewhere and grows as a common weed in some areas. *Broomleaf toadflax or Dalmatian toadflax ('' Linaria genistifolia'', syn. ''L. dalmatica''), a native of southe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisotropy
Anisotropy () is the property of a material which allows it to change or assume different properties in different directions, as opposed to isotropy. It can be defined as a difference, when measured along different axes, in a material's physical or mechanical properties (absorbance, refractive index, conductivity, tensile strength, etc.). An example of anisotropy is light coming through a polarizer. Another is wood, which is easier to split along its grain than across it. Fields of interest Computer graphics In the field of computer graphics, an anisotropic surface changes in appearance as it rotates about its geometric normal, as is the case with velvet. Anisotropic filtering (AF) is a method of enhancing the image quality of textures on surfaces that are far away and steeply angled with respect to the point of view. Older techniques, such as bilinear and trilinear filtering, do not take into account the angle a surface is viewed from, which can result in aliasing or bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquilegia
''Aquilegia'' (common names: granny's bonnet, columbine) is a genus of about 60–70 species of perennial plants that are found in meadows, woodlands, and at higher altitudes throughout the Northern Hemisphere, known for the spurred petals Puzey, J.R., Gerbode, S.J., Hodges, S.A., Kramer, E.M., Mahadevan, L. (2011) Evolution of ''Aquilegia'' spur length diversity through changes in cell anisotropy. Proceedings of the Royal Society B. of their flowers. Etymology The genus name Aquilegia comes from the Latin “Aquila”, or “eagle”; this is in obvious reference to the spurred, “hook” shapes within the blooms, that many gardeners say resemble an eagle's talons. Description Perennial herbs, with woody, erect stock, roots forming thick rhizomes. The basal leaves are compound, 1–3 ternate, blades 3-lobed -partite, and lobes lobulate and obtuse. The cauline leaves are similar to the basal ones, while the upper ones are bract like. The hermaphrodite (bisexual) flowers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbines
''Aquilegia'' (common names: granny's bonnet, columbine) is a genus of about 60–70 species of perennial plants that are found in meadows, woodlands, and at higher altitudes throughout the Northern Hemisphere, known for the spurred petals Puzey, J.R., Gerbode, S.J., Hodges, S.A., Kramer, E.M., Mahadevan, L. (2011) Evolution of ''Aquilegia'' spur length diversity through changes in cell anisotropy. Proceedings of the Royal Society B. of their flowers. Etymology The genus name Aquilegia comes from the Latin “Aquila”, or “eagle”; this is in obvious reference to the spurred, “hook” shapes within the blooms, that many gardeners say resemble an eagle's talons. Description Perennial herbs, with woody, erect stock, roots forming thick rhizomes. The basal leaves are compound, 1–3 ternate, blades 3-lobed -partite, and lobes lobulate and obtuse. The cauline leaves are similar to the basal ones, while the upper ones are bract like. The hermaphrodite (bisexual) flowers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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