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Pteridophyte
A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as " cryptogams", meaning that their means of reproduction is hidden. They are also the ancestors of the plants we see today. Ferns, horsetails (often treated as ferns), and lycophytes ( clubmosses, spikemosses, and quillworts) are all pteridophytes. However, they do not form a monophyletic group because ferns (and horsetails) are more closely related to seed plants than to lycophytes. "Pteridophyta" is thus no longer a widely accepted taxon, but the term ''pteridophyte'' remains in common parlance, as do ''pteridology'' and ''pteridologist'' as a science and its practitioner, for example by the International Association of Pteridologists and the Pteridophyte Phylogeny Group. Etymology The name ''Pteridophyte'' is a Neo-Latin compound word created by English speakers around 1880. It is for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissues that conduct water and nutrients, and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaf, leaves called megaphylls that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled Fiddlehead fern, fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate (Polypodiidae (plant), Polypodiidae) and eusporangiate ferns, the latter group including horsetails, Psilotaceae, whisk ferns, marattioid ferns, and ophioglossoid ferns. The fern crown group, consisting of the leptosporangiates and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clubmoss
Lycopodiopsida is a class of vascular plants also known as lycopsids, lycopods, or lycophytes. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching stems bearing simple leaves called microphylls and reproduce by means of spores borne in sporangia on the sides of the stems at the bases of the leaves. Although living species are small, during the Carboniferous, extinct tree-like forms ( Lepidodendrales) formed huge forests that dominated the landscape and contributed to coal deposits. The nomenclature and classification of plants with microphylls varies substantially among authors. A consensus classification for extant (living) species was produced in 2016 by the Pteridophyte Phylogeny Group (PPG I), which places them all in the class Lycopodiopsida, which includes the classes Isoetopsida and Selaginellopsida used in other systems. (See Table 2.) Alternative classification systems have used ranks from div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracheophyta
Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Tissue (biology), tissue (the phloem) to conduct products of photosynthesis. The group includes most embryophyte, land plants ( accepted known species) excluding mosses. Vascular plants include the clubmosses, Equisetum, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). They are contrasted with nonvascular plants such as mosses and green algae. Scientific names for the vascular plants group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato, 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 "hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptogam
A cryptogam (scientific name ''Cryptogamae'') is a plant, in the broad sense of the word, or a plant-like organism that share similar characteristics, such as being multicellular, photosynthetic, and primarily immobile, that reproduces via spores rather than through flowers or seeds. This broader definition can include algae, fungi, and certain bacteria (like cyanobacteria), even though they may belong to different biological kingdoms. Taxonomy The name ''Cryptogamae'' () means "hidden reproduction", meaning non-seed bearing plants. Other names, such as "thallophytes", "lower plants", and "spore plants" have occasionally been used. As a group, Cryptogamae are paired with the Phanerogamae or Spermatophyta, the seed plants. At one time, the cryptogams were formally recognised as a group within the plant kingdom. In his system for classification of all known plants and animals, Carl Linnaeus (1707–1778) divided the plant kingdom into 24 classes, one of which was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycopodiophyta
The lycophytes, when broadly circumscribed, are a group of vascular plants that include the clubmosses. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineages of extant (living) vascular plants; the group contains extinct plants that have been dated from the Silurian (ca. 425 million years ago). Lycophytes were some of the dominating plant species of the Carboniferous period, and included the tree-like Lepidodendrales, some of which grew over in height, although extant lycophytes are relatively small plants. The scientific names and the informal English names used for this group of plants are ambiguous. For example, "Lycopodiophyta" and the shorter "Lycophyta" as well as the informal "lycophyte" may be used to include the extinct zosterophylls or to exclude them. Description Lycophytes reproduce by spores and have alternation of generations in which (like other vascular plants) the sporop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteridophyte Phylogeny Group
The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discovered through phylogenetic studies. In 2016, the group published a classification for extant pteridophytes, termed "PPG I". The paper had 94 authors (26 principal and 68 additional). The classification was presented as a consensus classification supported by the community of fern taxonomists. Alternative classifications of ferns exist and are preferred by some. PPG I A first classification, PPG I, was produced in 2016, covering only extant (living) pteridophytes. The classification was rank-based, using the ranks of class, subclass, order, suborder, family, subfamily and genus. Phylogeny The classification was based on a consensus phylogeny, shown below to the level of order. The very large order Polypodiales was divided into two subord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Plant
Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Tissue (biology), tissue (the phloem) to conduct products of photosynthesis. The group includes most embryophyte, land plants ( accepted known species) excluding mosses. Vascular plants include the clubmosses, Equisetum, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). They are contrasted with nonvascular plants such as mosses and green algae. Scientific names for the vascular plants group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato, 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 "hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiomorphies
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and synapomorphy all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, frogs, all have backbones and none are either birds nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Plant
The embryophytes () are a clade of plants, also known as Embryophyta (Plantae ''sensu strictissimo'') () or land plants. They are the most familiar group of photoautotrophs that make up the vegetation on Earth's dry lands and wetlands. Embryophytes have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of freshwater charophyte green algae as a sister taxon of Charophyceae, Coleochaetophyceae and Zygnematophyceae. Embryophytes consist of the bryophytes and the polysporangiophytes. Living embryophytes include hornworts, liverworts, mosses, lycophytes, ferns, gymnosperms and angiosperms (flowering plants). Embryophytes have biological life cycle, diplobiontic life cycles. The embryophytes are informally called "land plants" because they thrive primarily in Terrestrial ecosystem, terrestrial habitats (despite aquatic plant, some members having evolved secondarily to live once again in semiaquatic/aquatic habitats), while the related green algae ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Tissue
Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant. The cells in vascular tissue are typically long and slender. Since the xylem and phloem function in the conduction of water, minerals, and nutrients throughout the plant, it is not surprising that their form should be similar to pipes. The individual cells of phloem are connected end-to-end, just as the sections of a pipe might be. As the plant grows, new vascular tissue differentiates in the growing tips of the plant. The new tissue is aligned with existing vascular tissue, maintaining its connection throughout the plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternation Of Generations
Alternation of generations (also known as metagenesis or heterogenesis) is the predominant type of life cycle in plants and algae. In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte. A mature sporophyte produces haploid spores by meiosis, a process which reduces the number of chromosomes to half, from two sets to one. The resulting haploid spores germinate and grow into multicellular haploid gametophytes. At maturity, a gametophyte produces gametes by mitosis, the normal process of cell division in eukaryotes, which maintains the original number of chromosomes. Two haploid gametes (originating from different organisms of the same species or from the same organism) fuse to produce a diploid zygote, which divides repeatedly by mitosis, developing into a multicellular diploid sporophyte. This cycle, from gametophyte to sporophyte (or equally from sporophyte to gametophyte), is the way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
