|
Haplomitriopsida
Haplomitriopsida is a newly recognized class of liverworts comprising fifteen species in three genera. Recent cladistic analyses of nuclear, mitochondrial, and plastid gene sequences place this monophyletic group as the basal sister group to all other liverworts. The group thus provides a unique insight into the early evolution of liverworts in particular and of land plants in general. Description Plants of ''Treubia'' grow as a prostrate leafy thallus. The bifid leaves extend like wings on either side of the midrib, or may be folded upwards and pressed close together, giving the plants a ruffled appearance. By contrast, '' Haplomitrium'' grows as a subterranean rhizome with erect leafy stems. The thin, rounded leaves are arranged around the upright stems, giving the appearance of a soft moss. The species '' Haplomitrium ovalifolium'' of Australia often has bifid leaves that are asymmetrical, somewhat like those in ''Treubia''. ''Haplomitrium'' has a number of unique c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marchantiophyta
The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information. It is estimated that there are about 9000 species of liverworts. Some of the more familiar species grow as a flattened leafless thallus, but most species are leafy with a form very much like a flattened moss. Leafy species can be distinguished from the apparently similar mosses on the basis of a number of features, including their single-celled rhizoids. Leafy liverworts also differ from most (but not all) mosses in that their leaves never have a costa (present in many mosses) and may bear marginal cilia (very rare in mosses). Other differences are not universal for all mosses and liverworts, but the occurrence of leaves arranged in three ranks, the presence of deep lobes or segmented leaves, or a lack of clearly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplomitrium Hookeri
''Haplomitrium hookeri'', the Hooker's flapwort, is a species of liverwort from the United Kingdom. References Plants described in 1813 Flora of Great Britain Calobryales {{bryophyte-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizome
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards. A rhizome is the main stem of the plant that runs underground horizontally. A stolon is similar to a rhizome, but a stolon sprouts from an existing stem, has long internodes, and generates new shoots at the end, such as in the strawberry plant. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, and generate new upward-growing shoots from the top of the nodes. A stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, e.g. the potato, which is a modified stolon. The term "tuber" is often used imprecisely and is sometimes appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marchantiopsida
Marchantiopsida is a class of liverworts within the phylum Marchantiophyta. The species in this class are known as complex thalloid liverworts. The species in this class are widely distributed and can be found worldwide. Phylogeny Based on the work by Villarreal et al. 2015 Taxonomy * Blasiidae He-Nygrén et al. 2006 ** Blasiales Stotl. & Crand.-Stotl. 2000 *** Blasiaceae H.Klinggr. 1858 *** † Treubiitaceae Schuster 1980 * Marchantiidae Engl. 1893 sensu He-Nygrén et al. 2006 ** Lunulariales H.Klinggr. 2006 *** Lunulariaceae H.Klinggr. 1858 ** Marchantiales Limpr. 1877 (complex thalloids) *** Aytoniaceae Cavers 1911 ebouliaceae; Grimaldiaceae*** Cleveaceae Cavers 1911 auteriaceae*** Conocephalaceae Müll.Frib. ex Grolle 1972 *** Corsiniaceae Engl. 1892 *** Cyathodiaceae Stotler & Crand.-Stotl. 2000 *** Dumortieraceae Long 2006 *** Exormothecaceae Müll.Frib. ex Grolle 1972 *** Marchantiaceae Lindl. 1836 *** Monocleaceae A.B.Frank 1877 *** Monosoleniaceae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Cell
Plant cells are the cells present in green plants, photosynthetic eukaryotes of the kingdom Plantae. Their distinctive features include primary cell walls containing cellulose, hemicelluloses and pectin, the presence of plastids with the capability to perform photosynthesis and store starch, a large vacuole that regulates turgor pressure, the absence of flagella or centrioles, except in the gametes, and a unique method of cell division involving the formation of a cell plate or phragmoplast that separates the new daughter cells. Characteristics of plant cells * Plant cells have cell walls, constructed outside the cell membrane and composed of cellulose, hemicelluloses, and pectin. Their composition contrasts with the cell walls of fungi, which are made of chitin, of bacteria, which are made of peptidoglycan and of archaea, which are made of pseudopeptidoglycan. In many cases lignin or suberin are secreted by the protoplast as secondary wall layers inside the primary cell wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Body
An oil body is a lipid-containing structure found in plant cells. The term can refer to at least two distinct kinds of structures in different kinds of plants. Oil bodies in liverworts Liverwort complex oil bodies are structures unique to liverworts that contain isoprenoid essential oils and are surrounded by a single membrane. The size, shape, color, and number of oil bodies per cell is characteristic of certain species and may be used to identify these. Oil bodies in vascular plants Some species of vascular plants also contain intracellular structures called oil bodies. Vascular plant oil bodies consist mainly of triacylglycerols surrounded by a layer consisting of phospholipid Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids ty ...s and the protein oleosin. These oil bodies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
