Banded Tube

	Banded Tube Banded tubes are a type of phytoclast consisting of micrometre-scale tubes with a banded internal ornamentation, and known from terrestrial/freshwater settings from the Early Silurian onwards. The bands on the walls were an early improvisation to aid the easy flow of water, and served as tracheids, although they are not equivalent in their construction. Banded tubes were lignified, giving them a more rigid structure than hydroids, allowing them to cope with higher levels of water pressure. Banded tubes have a markedly different ultrastructure from plant tracheids, and display a wide variety of wall structures, which implies that they were produced by a variety of different organisms, or perhaps were widely variable within a single nematophyte-like organism. Proposed functions include water transport, feeding (cf. fungal hyphae), and anchorage (cf. rhizoids). Some banded tubes can be assigned to genera such as '' Nematoplexus'' and ''Nematasketum ''Nematasketum'' (sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Phytoclast Phytoclasts are microscopic plant fragments present in the fossil record, usually found in palynological preparations and acid macerations, and include banded tubes and various nematophytes. References Fossil record of plants Prehistoric plants {{paleobotany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Tracheid A tracheid is a long and tapered lignified cell in the xylem of vascular plants. It is a type of conductive cell called a tracheary element. Angiosperms use another type of tracheary element, called vessel elements, to transport water through the xylem. The main functions of tracheid cells are to transport water and inorganic salts, and to provide structural support for trees. There are often pits on the cell walls of tracheids, which allows for water flow between cells. Tracheids are dead at functional maturity and do not have a protoplast. The wood (softwood) of gymnosperms such as pines and other conifers is mainly composed of tracheids. Tracheids are also the main conductive cells in the primary xylem of ferns. The tracheid was first named after the German botanist Carl Gustav Sanio in 1863, from the German ''Tracheide''. Evolution Tracheids were the main conductive cells found in early vascular plants. In the first 140-150 million years of vascular plant evolution, trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Hydroid (botany) A hydroid is a type of vascular cell that occurs in certain bryophytes. In some mosses such as members of the Polytrichaceae family, hydroids form the innermost layer of cells in the stem. At maturity they are long, colourless, thin walled cells of small diameter, containing water but no living protoplasm. Collectively, hydroids function as a conducting tissue, known as the hydrome, transporting water and minerals drawn from the soil. They are surrounded by bundles of living cells known as leptoids which carry sugars and other nutrients in solution. The hydroids are analogous to the tracheids of vascular plants but there is no lignin present in the cell walls to provide structural support. Hydroids have been found in some fossilised plants from the Rhynie chert, including ''Aglaophyton'', where they were initially mistaken for xylem tracheids. See also * Leptoid, a related sucrose-transporting vessel analogous to the phloem Phloem (, ) is the living tissue in vascular plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Nematophyte The Nematophyta or nematophytes are a paraphyletic group of land organisms, probably including some plants as well as algae known only from the fossil record, from the Silurian period until the early Devonian Rhynie chert. The type genus ''Nematothallus'', which typifies the group, was first described by Lang in 1937, who envisioned it being a thallose plant with tubular features and sporophyte A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...s, covered by a cuticle which preserved impressions of the underlying cells. He had found abundant disaggregated remains of all three features, none of which were connected to another, leaving his reconstruction of the phytodebris as parts of a single organism highly conjectural. No reproductive or vegetative structures common to the land ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Nematoplexus ''Nematoplexus rhyniensis'' is a fossil known from the Rhynie chert assigned to the nematophytes. It comprises a loose mass of coily aseptate tubes. Tubes which may have originated from a ''Nematoplexus''-like plant are known from earlier Silurian sediments Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand a .... References Prehistoric plant genera Silurian plants {{silurian-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Nematasketum ''Nematasketum'' (sometimes incorrectly spelt nematosketum) is a nematophyte with internally thickened tubes. It is thought to be terrestrial or freshwater, and seems to be aligned with the fungi. References Silurian plants {{silurian-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]