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Rhizanthella
''Rhizanthella'', commonly known as underground orchids, is a genus of flowering plants in the orchid family, Orchidaceae and is endemic to Australia. All are leafless, living underground in symbiosis with mycorrhizal fungi. The inflorescence is a head of flowers held at, or just above the ground but mostly covered by soil or leaf litter and little is known about the mechanism of pollination. Description Orchids in the genus ''Rhizanthella'' are mostly underground, perennial, sympodial, mycotrophic herbs with fleshy underground stems which produce new shoots at nodes where there are colourless leaf-like cataphylls. There are no roots and new tubers form at the end of short stems. The leaves are reduced to scale-like structures lacking chlorophyll, pressed against and sheathing the stems. The inflorescence is a head containing many flowers and is held at, or just above ground level but the head is usually covered with leaf litter or soil. The head is surrounded by a large number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizanthella Gardneri
''Rhizanthella gardneri'', commonly known as western underground orchid, is a species of flowering plant in the orchid family and is endemic to the southwest of Western Australia. It is a herb that spends its entire life cycle, including flowering, at or below the soil surface. A head of up to 100 small reddish to cream-coloured, inward facing flowers surrounded by large, cream-coloured bracts with a horizontal rhizome is produced between May and July. Description ''Rhizanthella gardneri'' is a leafless, sympodial herb with a horizontal rhizome below the soil surface. Beginning in late May to early June, the plant produces up to 100 small, inward-facing pinkish to deep red and cream coloured flowers wide, surrounded by six to twelve pinkish-cream bracts. The bracts curve over the flowers, forming a tulip-like head and leaving a small opening at, or a few millimetres above the soil surface. After pollination, each flower produces a fleshy, berry-like fruit containing up to 150 se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orchidaceae
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering plants. The Orchidaceae have about 28,000 currently accepted species, distributed in about 763 genera. (See ''External links'' below). The determination of which family is larger is still under debate, because verified data on the members of such enormous families are continually in flux. Regardless, the number of orchid species is nearly equal to the number of bony fishes, more than twice the number of bird species, and about four times the number of mammal species. The family encompasses about 6–11% of all species of seed plants. The largest genera are ''Bulbophyllum'' (2,000 species), ''Epidendrum'' (1,500 species), ''Dendrobium'' (1,400 species) and ''Pleurothallis'' (1,000 species). It also includes ''Vanilla'' (the genus of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum. Hence chlorophyll-containing tissues appear green because green light, diffusively reflected by structures like cell walls, is less absorbed. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll ''a'' and ''b''. History Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. The presence of magnesium in chlorophyll was discovered in 1906, and was that element's first detection in living tissue. After initial work done by German chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of 'junk' DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome. The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The International Human Genome Project reported the sequence of the genome for ''Homo sapiens'' in 200The Human Genome Project although the initial "finished" sequence was missing 8% of the genome consisting mostly of repetitive sequences. With advancements in technology that could handle sequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organelle
In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as organs are to the body, hence ''organelle,'' the suffix ''-elle'' being a diminutive. Organelles are either separately enclosed within their own lipid bilayers (also called membrane-bound organelles) or are spatially distinct functional units without a surrounding lipid bilayer (non-membrane bound organelles). Although most organelles are functional units within cells, some function units that extend outside of cells are often termed organelles, such as cilia, the flagellum and archaellum, and the trichocyst. Organelles are identified by microscopy, and can also be purified by cell fractionation. There are many types of organelles, particularly in eukaryotic cells. They include structures that make up the endomembrane system (such as the nuclear envelope, endoplasmic reticulum, and G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
