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Rhyniophyta
The rhyniophytes are a group of extinct early vascular plants that are considered to be similar to the genus ''Rhynia'', found in the Early Devonian (around ). Sources vary in the name and rank used for this group, some treating it as the class Rhyniopsida, others as the subdivision Rhyniophytina or the division Rhyniophyta. The first definition of the group, under the name Rhyniophytina, was by Banks, since when there have been many redefinitions, including by Banks himself. "As a result, the Rhyniophytina have slowly dissolved into a heterogeneous collection of plants ... the group contains only one species on which all authors agree: the type species ''Rhynia gwynne-vaughanii''". When defined very broadly, the group consists of plants with dichotomously branched, naked aerial axes ("stems") with terminal spore-bearing structures (sporangia). The rhyniophytes are considered to be stem group tracheophytes (vascular plants). Definitions The group was described as a subdivision o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracheophyta
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Plant
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysporangiophyte
Polysporangiophytes, also called polysporangiates or formally Polysporangiophyta, are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that bear sporangia. The name literally means 'many sporangia plant'. The clade includes all land plants (embryophytes) except for the bryophytes (liverworts, mosses and hornworts) whose sporophytes are normally unbranched, even if a few exceptional cases occur. While the definition is independent of the presence of vascular tissue, all living polysporangiophytes also have vascular tissue, i.e., are vascular plants or tracheophytes. Extinct polysporangiophytes are known that have no vascular tissue and so are not tracheophytes. Early polysporangiophytes History of discovery Paleobotanists distinguish between micro- and megafossils. Microfossils are primarily spores, either single or in groups. Megafossils are preserved parts of plants large enough to show structure, such as stem cross-sections or branching patte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysporangiophyte
Polysporangiophytes, also called polysporangiates or formally Polysporangiophyta, are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that bear sporangia. The name literally means 'many sporangia plant'. The clade includes all land plants (embryophytes) except for the bryophytes (liverworts, mosses and hornworts) whose sporophytes are normally unbranched, even if a few exceptional cases occur. While the definition is independent of the presence of vascular tissue, all living polysporangiophytes also have vascular tissue, i.e., are vascular plants or tracheophytes. Extinct polysporangiophytes are known that have no vascular tissue and so are not tracheophytes. Early polysporangiophytes History of discovery Paleobotanists distinguish between micro- and megafossils. Microfossils are primarily spores, either single or in groups. Megafossils are preserved parts of plants large enough to show structure, such as stem cross-sections or branching patte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eogaspesiea
''Eogaspesiea'' was a genus of Early Devonian rhyniophyte The rhyniophytes are a group of extinct early vascular plants that are considered to be similar to the genus '' Rhynia'', found in the Early Devonian (around ). Sources vary in the name and rank used for this group, some treating it as the class ... with a tangled mess of branching axes that reached 10 cm in length. These probably emanated from a rhizome. Its (probably) alete spores had thin walls. References Devonian plants Prehistoric plant genera {{devonian-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Culullitheca
''Culullitheca'' was a genus of land plant The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes () have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as sist ... with branching axes. It is known from charcoalified Early Devonian deposits, its type locality being the Brown Clee Hill lagerstätten. Its spores formed permanent dyads. References Silurian plants Devonian plants Prehistoric plant genera {{devonian-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooksonia
''Cooksonia'' is an extinct group of primitive land plants, treated as a genus, although probably not monophyletic. The earliest ''Cooksonia'' date from the middle of the Silurian (the Wenlock epoch); the group continued to be an important component of the flora until the end of the Early Devonian, a total time span of . While ''Cooksonia'' fossils are distributed globally, most type specimens come from Britain, where they were first discovered in 1937. ''Cooksonia'' includes the oldest known plant to have a stem with vascular tissue and is thus a transitional form between the primitive non-vascular bryophytes and the vascular plants. Description Only the sporophyte phase of ''Cooksonia'' is currently known (i.e. the phase which produces spores rather than gametes). Individuals were small, a few centimetres tall, and had a simple structure. They lacked leaves, flowers and roots—although it has been speculated that they grew from a rhizome that has not been preserved. They had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caia (plant)
''Caia'' is a genus of small fossil plants of Late Silurian age (around ). The diagnostic characters are naked parallel-sided axes branching isotomously, terminating in vertically elongate sporangia (spore-forming organs) which bear spinous emergences particularly at the distal ends. Spores are trilete and retusoid. The only known species is from Hereford, England. Cladistic analysis suggests that the genus may belong to the Horneophytopsida, a class of the polysporangiophytes, as it lacks vascular tissue and has branched stems bearing sporangia. For the cladogram, see the Horneophytopsida The Horneophytopsida, informally called horneophytes, are a class of extinct plants which consisted of branched stems without leaves, true roots or vascular tissue, found from the Late Silurian to the Early Devonian (around ). They are the sim ... article. References Silurian plants Prehistoric plant genera Pridoli first appearances Silurian extinctions {{silurian-plant-stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aberlemnia
''Aberlemnia'' is a genus of extinct vascular plants of the Early Devonian (around ), which consisted of leafless stems with terminal spore-forming organs (sporangia). Fossils found in Scotland were initially described as ''Cooksonia caledonica''. A later review, which included new and more complete fossils from Brazil, showed that the specimens did not fit the circumscription of the genus ''Cooksonia''; accordingly a new genus ''Aberlemnia'' was proposed. Description Fossils from which the genus was first described were found in the Aberlemno quarry, Scotland. Other fossils now assigned to ''Aberlemnia caledonica'' have been found in Wales, Brazil and possibly Bolivia. Plants consisted of smooth leafless stems (axes) up to 1.4 mm wide, decreasing in width at each branching. Specimens branched up to five times, at angles between 25 and 55°, mainly dichotomously, although those from Brazil had some trichotomies. Spore-forming organs or sporangia were borne at the ends of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooksonioids
''Cooksonia'' is an extinct group of primitive land plants, treated as a genus, although probably not monophyletic. The earliest ''Cooksonia'' date from the middle of the Silurian (the Wenlock epoch); the group continued to be an important component of the flora until the end of the Early Devonian, a total time span of . While ''Cooksonia'' fossils are distributed globally, most type specimens come from Britain, where they were first discovered in 1937. ''Cooksonia'' includes the oldest known plant to have a stem with vascular tissue and is thus a transitional form between the primitive non-vascular bryophytes and the vascular plants. Description Only the sporophyte phase of ''Cooksonia'' is currently known (i.e. the phase which produces spores rather than gametes). Individuals were small, a few centimetres tall, and had a simple structure. They lacked leaves, flowers and roots—although it has been speculated that they grew from a rhizome that has not been preserved. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euphyllophytina
The euphyllophytes are a clade of plants within the tracheophytes (the vascular plants). The group may be treated as an unranked clade, a division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a method for computing the result of mathematical division Military *Division (military), a formation typically consisting ... under the name Euphyllophyta or a subdivision under the name Euphyllophytina. The euphyllophytes are characterized by the possession of true leaves ("megaphylls"), and comprise one of two major lineages of extant vascular plants. As shown in the cladogram below, the euphyllophytes have a sister relationship to the lycopodiophytes or lycopsids. Unlike the lycopodiophytes, which consist of relatively few presently living or extant taxa, the euphyllophytes comprise the vast majority of vascular plant lineages that have evolved since both groups shared a common ancestor more than 400 mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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