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The embryophytes are the most familiar group of plants. The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex The Archaeplastida or Primoplantae are a major line of Eukaryotes comprising the land plants green and Red algae and a small Plants are living Organisms belonging to the kingdom Plantae. Bryophytes are all Embryophytes ('land Plants) that are non-vascular: they have tissues and enclosed reproductive systems but they lack Vascular tissue The Marchantiophyta are a division of Bryophyte Plants commonly referred to as hepatics or liverworts. This is an article about the non-vascular plants The name Hornwort is also often applied to an aquatic plant Ceratophyllum demersum in the family Ceratophyllaceae Mosses are small soft Plants that are typically 1–10 cm (0 Horneophytopsida is a class of early Vascular plants including the genera Caia, Tortilicaulis, and Horneophyton Vascular plants (also known as tracheophytes or higher plants) are those Plants that have lignified tissues for conducting Rhyniophyta is a division of early Vascular plants including the class Rhyniopsida. The Zosterophyllaceae or Zosterophylls (class Zosterophyllopsida) were probably Stem-group Lycophytes forming a sister group to the ancestors The Division Lycopodiophyta (sometimes called Lycophyta) is a tracheophyte subdivision of the Kingdom Plantae It is the oldest extant (living A division of early land plant from the Devonian containing genera such as Psilophyton. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta The spermatophytes (from the Greek word "Σπερματόφυτα" (also known as phanerogams) comprise those Plants that produce Seeds They are Pteridospermatophyta, also called seed ferns, is an extinct Spermatophyte group of the Plantae kingdom. Cycads are a group of Seed plants characterized by a large crown of compound leaves and a stout trunk. The Ginkgoaceae is a family of Gymnosperms which appeared during the Mesozoic Era of which the only extant representative is Ginkgo biloba The Plant division Gnetophyta or gnetophytes comprise three related families of Woody plants grouped in the Gymnosperms The gnetophytes differ from The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group Plants are living Organisms belonging to the kingdom Plantae. They include trees, flowers, ferns, mosses, and various other green land plants. A tree is a perennial Woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Mosses are small soft Plants that are typically 1–10 cm (0 All are complex multicellular eukaryotes with specialized reproductive organs. Multicellular organisms are Organisms consisting of more than one cell, and having Differentiated cells that perform specialized functions Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex With very few exceptions, embryophytes obtain their energy through photosynthesis (that is, by absorbing light); and they synthesize their food from carbon dioxide. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Embryophyta may be distinguished from chlorophyll-using multicellular algae by having sterile tissue within the reproductive organs. Chlorophyll is a green Pigment found in most Plants Algae and Cyanobacteria. Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms Furthermore, embryophytes are primarily adapted for life on land, although some are secondarily aquatic. Aquatic plants &mdash also called hydrophytic plants or hydrophytes &mdash are plants that have adapted to living in or on aquatic environments Accordingly, they are often called land plants or terrestrial plants.
Embryophytes developed from complex green algae (Chlorophyta) during the Paleozoic era. The green algae (singular green alga) are the large group of Algae from which the Embryophytes (higher plants emerged Chlorophyta, a division of Green algae, of mostly aquatic Photosynthetic Eukaryotic organisms The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" The Charales or stoneworts appear to be the best living illustration of that developmental step. The Charales are Algae in the division Charophyta. They are green plants believed to be the closest relatives of the green land plants. These alga-like plants undergo an alternation between haploid and diploid generations (respectively called gametophytes and sporophytes). The Alternation of phases (or generations) describes the life cycle of Plants Fungi and Protists A multicellular Diploid phase alternates "Haplo" redirects here For the fictional character see The Death Gate Cycle. "Haplo" redirects here For the fictional character see The Death Gate Cycle. In Plants and Algae that undergo Alternation of generations, a gametophyte is the multicellular structure or phase that is Haploid, containing All land plants and some Algae, have life cycles in which a haploid Gametophyte generation alternates with a Diploid sporophyte, the generation of a In the first embryophytes, however, the sporophytes became very different in structure and function, remaining small and dependent on the parent for their entire brief life. Such plants are informally called 'bryophytes'. Bryophytes are all Embryophytes ('land Plants) that are non-vascular: they have tissues and enclosed reproductive systems but they lack Vascular tissue They include three surviving groups:
- Bryophyta (mosses)
- Anthocerotophyta (hornworts)
- Marchantiophyta (liverworts)
All of the above 'bryophytes' are relatively small and are usually confined to moist environments, relying on water to disperse their spores. Mosses are small soft Plants that are typically 1–10 cm (0 This is an article about the non-vascular plants The name Hornwort is also often applied to an aquatic plant Ceratophyllum demersum in the family Ceratophyllaceae The Marchantiophyta are a division of Bryophyte Plants commonly referred to as hepatics or liverworts. In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions Other plants, better adapted to terrestrial conditions, appeared during the Silurian period. The Silurian is a geologic period and system that extends from the end of the Ordovician period about 443 During the Devonian period, they diversified and spread to many different land environments, becoming the vascular plants or tracheophytes. The Devonian is a geologic period and system of the Paleozoic era spanning from to million years ago. Vascular plants (also known as tracheophytes or higher plants) are those Plants that have lignified tissues for conducting Vascular plants (also known as tracheophytes or higher plants) are those Plants that have lignified tissues for conducting Tracheophyta have vascular tissues or tracheids, which transport water throughout the body, and an outer layer or cuticle that resists drying out. Tracheids are elongated cells in the Xylem of Vascular plants serving in the transport of water and mineral salts Desiccation is the state of extreme dryness or the process of extreme drying In most vascular plants, the sporophyte is the dominant individual, and develops true leaves, stems, and roots, while the gametophyte remains very small. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. A stem is one of two main structural axes of a Vascular plant. ROOT is an object-oriented program and library developed by CERN.
Many vascular plants, however, still disperse using spores. They include two extant groups:
- Lycopodiophyta (clubmosses)
- Pteridophyta (ferns, whisk ferns, and horsetails)
Other groups, which first appeared towards the end of the Paleozoic era, reproduce using desiccation-resistant capsules called seeds. The Division Lycopodiophyta (sometimes called Lycophyta) is a tracheophyte subdivision of the Kingdom Plantae It is the oldest extant (living Lycopodiopsida is a class of plants often loosely grouped as the fern allies, and includes the clubmosses A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Equisetum is a genus of Vascular plants that reproduce by spores rather than seeds Desiccation is the state of extreme dryness or the process of extreme drying A seed (in some plants referred to as a kernel) is a small embryonic Plant enclosed in a covering called the seed coat usually with some stored These groups are accordingly called spermatophytes or seed plants. The spermatophytes (from the Greek word "Σπερματόφυτα" (also known as phanerogams) comprise those Plants that produce Seeds They are In these forms, the gametophyte is completely reduced, taking the form of single-celled pollen and ova, while the sporophyte begins its life enclosed within the seed. Pollen is a fine to coarse powder consisting of microgametophytes ( pollen grains) which produce the male Gametes (sperm cells of An ovum (plural ova) is a Haploid Female reproductive cell or Gamete. Some seed plants may even survive in extremely arid conditions, unlike their more water-bound precursors. The seed plants include the following extant groups:
- Cycadophyta (cycads)
- Ginkgophyta (ginkgo)
- Pinophyta (conifers)
- Gnetophyta (gnetae)
- Magnoliophyta (flowering plants)
The first four groups are referred to as gymnosperms, since the embryonic sporophyte is not enclosed until after pollination. Gymnosperm (Gymnospermae are a group of Spermatophyte seed-bearing Plants with Ovules on the edge or blade of an open Sporophyll, which are In contrast, among the flowering plants or angiosperms, the pollen has to grow a tube to penetrate the seed coat. The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group Angiosperms were the last major group of plants to appear, developing from gymnosperms during the Jurassic period, and then spreading rapidly during the Cretaceous. The Jurassic is a geologic period and system that extends from about Ma (million years ago to Ma that is from the end of the Triassic to the beginning The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of They are the predominant group of plants in most terrestrial biomes today. A terrestrial plant is one that grows on land Other types of plants are aquatic (living in water Epiphytic (living on trees but not Parasitic) A biome is a climatically and geographically defined area of ecologically similar climatic conditions such as communities of Plants Animals and
Note that the higher-level classification of plants varies considerably. Statistical classification is a procedure in which individual items are placed into groups based on quantitative information on one or more characteristics inherent in the items (referred Some authors have restricted the kingdom Plantae to include only embryophytes, others have given them various names and ranks. In biological Taxonomy, a kingdom or regnum is a Taxonomic rank in either (historically the highest rank or (in the new three-domain system Plants are living Organisms belonging to the kingdom Plantae. The groups listed here are often considered divisions or phyla, but have also been treated as classes, and they are occasionally compressed into as few as two divisions. A phylum ( Plural: phyla) is a Taxonomic rank between Kingdom and above Class. Some classifications, indeed, consider the term Embryophyta at the superphylum (superdivision) level, and include Land Plants and some Charophyceae in a subkingdom named Streptophyta. Streptophytina is formally a subdivision or subphylum (but sometimes used at the division level where more appropriate would be the use of the term Streptophyta see below
On a microscopic level, embryophyte cells remain very similar to those of green algae. They are eukaryotic, with a cell wall composed of cellulose and plastids surrounded by two membranes. Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex A cell wall is a tough flexible and sometimes fairly rigid layer surrounding a cell, located external to the Cell membrane, which provides the cell with structural Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4 Plastids are major Organelles found in plants and algae Plastids often contain pigments used in photosynthesis and the types of pigments present can change These usually take the form of chloroplasts, which conduct photosynthesis and store food in the form of starch, and characteristically are pigmented with chlorophylls a and b, generally giving them a bright green color. Chloroplasts are Organelles found in Plant cells and eukaryotic Algae that conduct Photosynthesis. Starch, CAS # 9005-25-8 Chemical formula (C6H10O5n is a Polysaccharide Embryophytes also generally have an enlarged central vacuole or tonoplast, which maintains cell turgor and keeps the plant rigid. In general vacuole functions include Removing unwanted structural debris Isolating materials that might be harmful or a threat to the cell Containing ' Turgor pressure' or turgidity is the main pressure of the cell contents against the Cell wall in Plant cells and bacteria cells determined by the water They lack flagella and centrioles except in certain gametes. A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it A Centriole is a barrel shaped Organelle found in most animal Eukaryotic cells though absent in Higher plants and Fungi. A gamete (from Ancient Greek γαμέτης; translated gamete = wife gametes = husband is a cell that fuses with another gamete
References
- ^ Gray, J. (1985). "The Microfossil Record of Early Land Plants: Advances in Understanding of Early Terrestrialization, 1970-1984". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 309 (1138): 167-195. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- Kenrick, Paul & Crane, Peter R. (1997). The Origin and Early Diversification of Land Plants: A Cladistic Study. Washington, D. C. : Smithsonian Institution Press. ISBN 1-56098-730-8.
- Raven, Peter H. , Evert, Ray F. , & Eichhorn, Susan E. (2005). Biology of Plants (7th ed. ). New York: W. H. Freeman and Company. ISBN 0-7167-1007-2.
- Smith, Alan R. , Kathleen M. Pryer, E. Schuettpelz, P. Korall, H. Schneider, & Paul G. Wolf. (2006). "A classification for extant ferns". Taxon 55(3): 705-731.
- Stewart, Wilson N. & Rothwell, Gar W. (1993). Paleobotany and the Evolution of Plants (2nd ed. ). Cambridge: Cambridge University Press. Cambridge University Press (known colloquially as CUP is a Publisher given a Royal Charter by Henry VIII in 1534 ISBN 0-521-38294-7.
- Taylor, Thomas N. & Taylor, Edith L. (1993). The Biology and Evolution of Fossil Plants. Englewood Cliffs, NJ: Prentice Hall. ISBN 0-13-651589-4.
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